Effects and mechanisms of cavidine protecting mice against LPS-induced endotoxic shock

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Weifeng, E-mail: liwf@mail.xjtu.edu.cn; Zhang,

LPS sensitized mice are usually considered as an experimental model of endotoxin shock. The present study aims to evaluate effects of cavidine on LPS-induced endotoxin shock. Mice were intraperitoneally administrated with cavidine (1, 3 and 10 mg/kg) or DEX (5 mg/kg) at 1 and 12 h before injecting LPS (30 mg/kg) intraperitoneally. Blood samples, liver, lung and kidney tissues were harvested after LPS injection. The study demonstrated that pretreatment with cavidine reduced the mortality of mice during 72 h after endotoxin injection. In addition, cavidine administration significantly attenuated histological pathophysiology features of LPS-induced injury in lung, liver and kidney. Furthermore,more » cavidine administration inhibited endotoxin-induced production of pro-inflammatory cytokines including TNF-α, IL-6 and HMGB1. Moreover, cavidine pretreatment attenuated the phosphorylation of mitogen-activated protein kinase primed by LPS. In summary, cavidine protects mice against LPS-induced endotoxic shock via inhibiting early pro-inflammatory cytokine TNF-α, IL-6 and late-phase cytokine HMGB1, and the modulation of HMGB1 may be related with MAPK signal pathway. - Highlights: • Cavidine significantly reduced mortality in mice during 72 h after LPS injection. • Cavidine attenuated histopathological changes in lung, liver and kidney. • Cavidine decreased the level of early inflammatory cytokine TNF-α, IL-6 in LPS- stimulated mice. • Cavidine inhibited late inflammatory cytokine HMGB1 through MAPK pathway.« less

Zinc protoporphyrin inhibition of lipopolysaccharide-, lipoteichoic acid-, and peptidoglycan-induced nitric oxide production through stimulating iNOS protein ubiquitination.

PubMed

Chow, Jyh-Ming; Lin, Hui-Yi; Shen, Shing-Chuan; Wu, Ming-Shun; Lin, Cheng-Wei; Chiu, Wen-Ta; Lin, Chien-Huang; Chen, Yen-Chou

2009-06-15

In the present study, zinc protoporphyrin (ZnPP), but not ferric protoporphyrin (FePP), tin protoporphyrin (SnPP), or zinc chloride (ZnCl(2)), at the doses of 0.5, 1, and 2 microM, dose-dependently inhibited lipopolysaccharide- (LPS), lipoteichoic acid (LTA), and peptidoglycan (PGN)-induced inducible nitric oxide (iNOS) and nitric oxide (NO) production with an increase in heme oxygenase 1 (HO-1) protein in RAW264.7 macrophages in a serum-free condition. NO inhibition and HO-1 induction by ZnPP were blocked by the separate addition of fetal bovine serum (FBS) and bovine serum albumin (BSA). A decrease in the iNOS/NO ratio and an increase in HO-1 protein by ZnPP were identified in three different conditions including ZnPP pretreatment, ZnPP co-treatment, and ZnPP post-treatment with LPS and LTA. Activation of c-Jun N-terminal kinases (JNKs) and extracellular regulated kinases (ERKs) were detected in LPS-, LTA-, and PGN-treated RAW264.7 cells, and iNOS/NO production was blocked by adding the JNK inhibitor, SP600125, but not the ERK inhibitor, PD98059. However, ZnPP addition potentiated ERK and JNK protein phosphorylation stimulated by LPS, LTA, and PGN. Increases in total protein ubiquitination and ubiquitinated iNOS proteins were detected in ZnPP-treated macrophages elicited by LPS according to Western and immunoprecipitation/Western blotting assays, respectively. The decrease in LPS-induced iNOS protein by ZnPP was reversed by adding the proteasome inhibitors MG132 and lactacystin. The reduction in HO-1 protein induced by ZnPP via transfection of HO-1 small interfering RNA did not affect the inhibitory effect of ZnPP against LPS-induced iNOS/NO production and protein ubiquitination induced by ZnPP in macrophages. Data of the present study provide the first evidence to support ZnPP effectively inhibiting inflammatory iNOS/NO production through activation of protein ubiquitination in a HO-1-independent manner in macrophages.

Zinc protoporphyrin inhibition of lipopolysaccharide-, lipoteichoic acid-, and peptidoglycan-induced nitric oxide production through stimulating iNOS protein ubiquitination

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chow, J.-M.; Lin, H.-Y.; Shen, S.-C.

2009-06-15

In the present study, zinc protoporphyrin (ZnPP), but not ferric protoporphyrin (FePP), tin protoporphyrin (SnPP), or zinc chloride (ZnCl{sub 2}), at the doses of 0.5, 1, and 2 {mu}M, dose-dependently inhibited lipopolysaccharide- (LPS), lipoteichoic acid (LTA), and peptidoglycan (PGN)-induced inducible nitric oxide (iNOS) and nitric oxide (NO) production with an increase in heme oxygenase 1 (HO-1) protein in RAW264.7 macrophages in a serum-free condition. NO inhibition and HO-1 induction by ZnPP were blocked by the separate addition of fetal bovine serum (FBS) and bovine serum albumin (BSA). A decrease in the iNOS/NO ratio and an increase in HO-1 protein bymore » ZnPP were identified in three different conditions including ZnPP pretreatment, ZnPP co-treatment, and ZnPP post-treatment with LPS and LTA. Activation of c-Jun N-terminal kinases (JNKs) and extracellular regulated kinases (ERKs) were detected in LPS-, LTA-, and PGN-treated RAW264.7 cells, and iNOS/NO production was blocked by adding the JNK inhibitor, SP600125, but not the ERK inhibitor, PD98059. However, ZnPP addition potentiated ERK and JNK protein phosphorylation stimulated by LPS, LTA, and PGN. Increases in total protein ubiquitination and ubiquitinated iNOS proteins were detected in ZnPP-treated macrophages elicited by LPS according to Western and immunoprecipitation/Western blotting assays, respectively. The decrease in LPS-induced iNOS protein by ZnPP was reversed by adding the proteasome inhibitors MG132 and lactacystin. The reduction in HO-1 protein induced by ZnPP via transfection of HO-1 small interfering RNA did not affect the inhibitory effect of ZnPP against LPS-induced iNOS/NO production and protein ubiquitination induced by ZnPP in macrophages. Data of the present study provide the first evidence to support ZnPP effectively inhibiting inflammatory iNOS/NO production through activation of protein ubiquitination in a HO-1-independent manner in macrophages.« less

Moringa fruit inhibits LPS-induced NO/iNOS expression through suppressing the NF-κ B activation in RAW264.7 cells.

PubMed

Lee, Hyo-Jin; Jeong, Yun-Jeong; Lee, Tae-Sung; Park, Yoon-Yub; Chae, Whi-Gun; Chung, Il-Kyung; Chang, Hyeun-Wook; Kim, Cheorl-Ho; Choi, Yung-Hyun; Kim, Wun-Jae; Moon, Sung-Kwon; Chang, Young-Chae

2013-01-01

In this study, we evaluated the anti-inflammatory effects of moringa (Moringa oleifera Lam.), a natural biologically active substance, by determining its inhibitory effects on pro-inflammatory mediators in lipopolysaccharide (LPS)-stimulated macrophage RAW264.7 cells. Extracts from different parts of moringa (root, leaf, and fruit) reduced LPS-induced nitric oxide (NO) release in a dose-dependent manner. The moringa fruit extract most effectively inhibited LPS-induced NO production and levels of inducible nitric oxide synthase (iNOS). The moringa fruit extract also was shown to suppress the production of inflammatory cytokines including IL-1β, TNF-α, and IL-6. Furthermore, moringa fruit extract inhibited the cytoplasmic degradation of I κ B -α and the nuclear translocation of p65 proteins, resulting in lower levels of NF -κ B transactivation. Collectively, the results of this study demonstrate that moringa fruit extract reduces the levels of pro-inflammatory mediators including NO , IL-1β, TNF-α, and IL-6 via the inhibition of NF -κ B activation in RAW264.7 cells. These findings reveal, in part, the molecular basis underlying the anti-inflammatory properties of moringa fruit extract.

SOX6 and PDCD4 enhance cardiomyocyte apoptosis through LPS-induced miR-499 inhibition.

PubMed

Jia, Zhuqing; Wang, Jiaji; Shi, Qiong; Liu, Siyu; Wang, Weiping; Tian, Yuyao; Lu, Qin; Chen, Ping; Ma, Kangtao; Zhou, Chunyan

2016-02-01

Sepsis-induced cardiac apoptosis is one of the major pathogenic factors in myocardial dysfunction. As it enhances numerous proinflammatory factors, lipopolysaccharide (LPS) is considered the principal mediator in this pathological process. However, the detailed mechanisms involved are unclear. In this study, we attempted to explore the mechanisms involved in LPS-induced cardiomyocyte apoptosis. We found that LPS stimulation inhibited microRNA (miR)-499 expression and thereby upregulated the expression of SOX6 and PDCD4 in neonatal rat cardiomyocytes. We demonstrate that SOX6 and PDCD4 are target genes of miR-499, and they enhance LPS-induced cardiomyocyte apoptosis by activating the BCL-2 family pathway. The apoptosis process enhanced by overexpression of SOX6 or PDCD4, was rescued by the cardiac-abundant miR-499. Overexpression of miR-499 protected the cardiomyocytes against LPS-induced apoptosis. In brief, our results demonstrate the existence of a miR-499-SOX6/PDCD4-BCL-2 family pathway in cardiomyocytes in response to LPS stimulation.

Lycorine inhibits lipopolysaccharide-induced iNOS and COX-2 up-regulation in RAW264.7 cells through suppressing P38 and STATs activation and increases the survival rate of mice after LPS challenge.

PubMed

Kang, Jingjing; Zhang, Yushun; Cao, Xiang; Fan, Jie; Li, Guilan; Wang, Qi; Diao, Ying; Zhao, Zhihui; Luo, Lan; Yin, Zhimin

2012-01-01

As a natural alkaloid extracted from Amaryllidaceae, lycorine shows various biological effects on tumor cells. Here we show that lycorine dose-dependently inhibited the LPS-induced up-regulation of nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) protein level in RAW264.7 cells. Besides, it also inhibited NO, PGE(2), TNF-α and IL-6 release from LPS-treated RAW264.7 cells. RT-PCR experiments showed that lycorine suppressed LPS-induced iNOS but not COX-2 gene expression. Moreover, lycorine decreased LPS-induced mortality in mice. Mechanistically, LPS-induced activation of P38 and STATs pathways was suppressed significantly by lycorine. In addition, lycorine did not interfere with the phosphorylation of ERK1/2, JNK1/2 and NF-κB pathways. In conclusion, lycorine inhibits LPS-induced production of pro-inflammatory mediators and increases the survival rate of mice after LPS challenge, suggesting that lycorine could play an anti-inflammatory role in response to LPS. Copyright © 2011 Elsevier B.V. All rights reserved.

Boric acid inhibits LPS-induced TNF-alpha formation through a thiol-dependent mechanism in THP-1 cells.

PubMed

Cao, Jun; Jiang, Liping; Zhang, Xiaomei; Yao, Xiaofeng; Geng, Chengyan; Xue, Xiangxin; Zhong, Laifu

2008-01-01

Oxidative stress plays an important role during inflammatory diseases and antioxidant administration to diminish oxidative stress may arrest inflammatory processes. Boron has been implicated to modulate certain inflammatory mediators and regulate inflammatory processes. Here we investigated the role of the tripeptide glutathione (GSH) in modulating the effects of boric acid (BA) on lipopolysaccharide (LPS)-induced tumor necrosis factor alpha (TNF-alpha) formation in THP-1 monocytes. Interestingly, we found that BA had no significant effects on both TNF-alpha production and intracellular GSH contents, whereas it could inhibit LPS-induced TNF-alpha formation and ameliorated the d,l-buthionine-S,R-sulfoximine (BSO)-induced GSH depletion. Twenty-four hour incubation with BSO induced a decrease of the intracellular GSH and an increase of TNF-alpha. Treatment with N-acetyl-l-cysteine (NAC) did not significantly increase intracellular content of GSH but significantly reduced the secretion of TNF-alpha. BSO-pretreatment for 24h enhanced the LPS-induced secretion and mRNA expression of TNF-alpha further. BA inhibited LPS-stimulated TNF-alpha formation was also seen after GSH depletion by BSO. These results indicate that BA may have anti-inflammatory effect in the LPS-stimulated inflammation and the effect of BA on TNF-alpha secretion may be induced via a thiol-dependent mechanism.

Esculin Inhibits the Inflammation of LPS-Induced Acute Lung Injury in Mice Via Regulation of TLR/NF-κB Pathways.

PubMed

Tianzhu, Zhang; Shumin, Wang

2015-08-01

In this study, we investigated anti-inflammatory effects of esculin (ESC) on lipopolysaccharide (LPS)-induced acute lung injury (ALI). ALI was induced in mice by intratracheal instillation of LPS, and ESC (20 and 40 mg/kg) was given orally 1 h prior to LPS administration. After 6 h, bronchoalveolar lavage fluid (BALF) and lung tissue were collected. ESC pretreatment decreased LPS-induced evident lung histopathological changes, lung wet-to-dry weight ratio, and lung myeloperoxidase activity. In addition, pretreatment with ESC inhibited inflammatory cells and proinflammatory cytokines including tumor necrosis factor-α (TNF-α), interleukin-1β, and interleukin-6 in BALF. Furthermore, we demonstrated that ESC inhibited the Toll-like receptor-2 (TLR2), Toll-like receptor-4 (TLR4), myeloid differentiation primary response gene-88 (MyD88), and nuclear factor-κB (NF-κB) p65 in LPS-induced ALI. The results indicated that the ESC had a protective effect on LPS-induced ALI in mice.

Caffeoyl glucosides from Nandina domestica inhibit LPS-induced endothelial inflammatory responses.

PubMed

Kulkarni, Roshan R; Lee, Wonhwa; Jang, Tae Su; Lee, JungIn; Kwak, Soyoung; Park, Mi Seon; Lee, Hyun-Shik; Bae, Jong-Sup; Na, MinKyun

2015-11-15

Endothelial dysfunction is a key pathological feature of many inflammatory diseases, including sepsis. In the present study, a new caffeoyl glucoside (1) and two known caffeoylated compounds (2 and 3) were isolated from the fruits of Nandina domestica Thunb. (Berberidaceae). The compounds were investigated for their effects against lipopolysaccharide (LPS)-mediated endothelial inflammatory responses. At 20 μM, 1 and 2 inhibited LPS-induced hyperpermeability, adhesion, and migration of leukocytes across a human endothelial cell monolayer in a dose-dependent manner suggesting that 1 and 2 may serve as potential scaffolds for the development of therapeutic agents to treat vascular inflammatory disorders. Copyright © 2015 Elsevier Ltd. All rights reserved.

Polyphenols from Lonicera caerulea L. Berry Inhibit LPS-Induced Inflammation through Dual Modulation of Inflammatory and Antioxidant Mediators.

PubMed

Wu, Shusong; Yano, Satoshi; Chen, Jihua; Hisanaga, Ayami; Sakao, Kozue; He, Xi; He, Jianhua; Hou, De-Xing

2017-06-28

Lonicera caerulea L. berry polyphenols (LCBP) are considered as major components for bioactivity. This study aimed to clarify the molecular mechanisms by monitoring inflammatory and antioxidant mediator actions in lipopolysaccharide (LPS)-induced mouse paw edema and macrophage cell model. LCBP significantly attenuated LPS-induced paw edema (3.0 ± 0.1 to 2.8 ± 0.1 mm, P < 0.05) and reduced (P < 0.05) serum levels of monocyte chemotactic protein-1 (MCP-1, 100.9 ± 2.3 to 58.3 ± 14.5 ng/mL), interleukin (IL)-10 (1596.1 ± 424.3 to 709.7 ± 65.7 pg/mL), macrophage inflammatory protein (MIP)-1α (1761.9 ± 208.3 to 1369.1 ± 56.4 pg/mL), IL-6 (1262.8 ± 71.7 to 499.0 ± 67.1 pg/mL), IL-4 (93.3 ± 25.7 to 50.7 ± 12.5 pg/mL), IL-12(p-70) (580.4 ± 132.0 to 315.2 ± 35.1 pg/mL), and tumor necrosis factor-α (TNF-α, 2045.5 ± 264.9 to 1270.7 ± 158.6 pg/mL). Cell signaling analysis revealed that LCBP inhibited transforming growth factor β activated kinase-1 (TAK1)-mediated mitogen-activated protein kinase (MAPK) and nuclear factor-κB (NF-κB) pathways, and enhanced the expression of nuclear factor (erythroid-derived 2)-like 2 (Nrf2) and manganese-dependent superoxide dismutase (MnSOD) in earlier response. Moreover, cyanidin 3-glucoside (C3G) and (-)-epicatechin (EC), two major components of LCBP, directly bound to TAK1. These data demonstrated that LCBP might inhibit LPS-induced inflammation by modulating both inflammatory and antioxidant mediators.

Lipopolysaccharide (LPS)-binding protein stimulates CD14-dependent Toll-like receptor 4 internalization and LPS-induced TBK1-IKKϵ-IRF3 axis activation.

PubMed

Tsukamoto, Hiroki; Takeuchi, Shino; Kubota, Kanae; Kobayashi, Yohei; Kozakai, Sao; Ukai, Ippo; Shichiku, Ayumi; Okubo, Misaki; Numasaki, Muneo; Kanemitsu, Yoshitomi; Matsumoto, Yotaro; Nochi, Tomonori; Watanabe, Kouichi; Aso, Hisashi; Tomioka, Yoshihisa

2018-05-14

Toll-like receptor 4 (TLR4) is an indispensable immune receptor for lipopolysaccharide (LPS), a major component of the Gram-negative bacterial cell wall. Following LPS stimulation, TLR4 transmits the signal from the cell surface and becomes internalized in an endosome. However, the spatial regulation of TLR4 signaling is not fully understood. Here, we investigated the mechanisms of LPS-induced TLR4 internalization and clarified the roles of the extracellular LPS-binding molecules, LPS-binding protein (LBP), and glycerophosphatidylinositol-anchored protein (CD14). LPS stimulation of CD14-expressing cells induced TLR4 internalization in the presence of serum, and an inhibitory anti-LBP mAb blocked its internalization. Addition of LBP to serum-free cultures restored LPS-induced TLR4 internalization to comparable levels of serum. The secretory form of the CD14 (sCD14) induced internalization but required a much higher concentration than LBP. An inhibitory anti-sCD14 mAb was ineffective for serum-mediated internalization. LBP lacking the domain for LPS transfer to CD14 and a CD14 mutant with reduced LPS binding both attenuated TLR4 internalization. Accordingly, LBP is an essential serum molecule for TLR4 internalization, and its LPS transfer to membrane-anchored CD14 (mCD14) is a prerequisite. LBP induced the LPS-stimulated phosphorylation of TBK1, IKKϵ, and IRF3, leading to IFN-β expression. However, LPS-stimulated late activation of NFκB or necroptosis were not affected. Collectively, our results indicate that LBP controls LPS-induced TLR4 internalization, which induces TLR adaptor molecule 1 (TRIF)-dependent activation of the TBK1-IKKϵ-IRF3-IFN-β pathway. In summary, we showed that LBP-mediated LPS transfer to mCD14 is required for serum-dependent TLR4 internalization and activation of the TRIF pathway. Copyright © 2018, The American Society for Biochemistry and Molecular Biology.

Lycium barbarum polysaccharide protects against LPS-induced ARDS by inhibiting apoptosis, oxidative stress, and inflammation in pulmonary endothelial cells.

PubMed

Chen, Lan; Li, Wen; Qi, Di; Wang, Daoxin

2018-04-01

Acute respiratory distress syndrome (ARDS) is a heterogenous syndrome characterised by diffuse alveolar damage, with an increase in lung endothelial and epithelial permeability. Lycium barbarum polysaccharide (LBP), the most biologically active fraction of wolfberry, possesses antiapoptotic and antioxidative effects in distinct situations. In the present study, the protective effects and potential molecular mechanisms of LBP against lipopolysaccharide (LPS)-induced ARDS were investigated in the mice and in the human pulmonary microvascular endothelial cells (HPMECs). The data indicated that pretreatment with LBP significantly attenuated LPS-induced lung inflammation and pulmonary oedema in vivo. LBP significantly reversed LPS-induced decrease in cell viability, increase in apoptosis and oxidative stress via inhibiting caspase-3 activation and intracellular reactive oxygen species (ROS) production in vitro. Moreover, the scratch assay verified that LBP restored the dysfunction of endothelial cells (ECs) migration induced by LPS stimulation. Furthermore, LBP also significantly suppressed LPS-induced NF-κB activation, and subsequently reversed the release of cytochrome c. These results showed the antiapoptosis and antioxidant LBP could partially protect against LPS-induced ARDS through promoting the ECs survival and scavenging ROS via inhibition of NF-κB signalling pathway. Thus, LBP could be potentially used for ARDS against pulmonary inflammation and pulmonary oedema.

Okanin, effective constituent of the flower tea Coreopsis tinctoria, attenuates LPS-induced microglial activation through inhibition of the TLR4/NF-κB signaling pathways

NASA Astrophysics Data System (ADS)

Hou, Yue; Li, Guoxun; Wang, Jian; Pan, Yingni; Jiao, Kun; Du, Juan; Chen, Ru; Wang, Bing; Li, Ning

2017-04-01

The EtOAc extract of Coreopsis tinctoria Nutt. significantly inhibited LPS-induced nitric oxide (NO) production, as judged by the Griess reaction, and attenuated the LPS-induced elevation in iNOS, COX-2, IL-1β, IL-6 and TNF-α mRNA levels, as determined by quantitative real-time PCR, when incubated with BV-2 microglial cells. Immunohistochemical results showed that the EtOAc extract significantly decreased the number of Iba-1-positive cells in the hippocampal region of LPS-treated mouse brains. The major effective constituent of the EtOAc extract, okanin, was further investigated. Okanin significantly suppressed LPS-induced iNOS expression and also inhibited IL-6 and TNF-α production and mRNA expression in LPS-stimulated BV-2 cells. Western blot analysis indicated that okanin suppressed LPS-induced activation of the NF-κB signaling pathway by inhibiting the phosphorylation of IκBα and decreasing the level of nuclear NF-κB p65 after LPS treatment. Immunofluorescence staining results showed that okanin inhibited the translocation of the NF-κB p65 subunit from the cytosol to the nucleus. Moreover, okanin significantly inhibited LPS-induced TLR4 expression in BV-2 cells. In summary, okanin attenuates LPS-induced activation of microglia. This effect may be associated with its capacity to inhibit the TLR4/NF-κB signaling pathways. These results suggest that okanin may have potential as a nutritional preventive strategy for neurodegenerative disorders.

Usefulness of ELISA Methods for Assessing LPS Interactions with Proteins and Peptides

PubMed Central

Martínez-Sernández, Victoria; Orbegozo-Medina, Ricardo A.; Romarís, Fernanda; Paniagua, Esperanza; Ubeira, Florencio M.

2016-01-01

Lipopolysaccharide (LPS), the major constituent of the outer membrane of Gram-negative bacteria, can trigger severe inflammatory responses during bacterial infections, possibly leading to septic shock. One approach to combatting endotoxic shock is to neutralize the most conserved part and major mediator of LPS activity (lipid A) with LPS-binding proteins or peptides. Although several available assays evaluate the biological activity of these molecules on LPS (e.g. inhibition of LPS-induced TNF-α production in macrophages), the development of simple and cost-effective methods that would enable preliminary screening of large numbers of potential candidate molecules is of great interest. Moreover, it would be also desirable that such methods could provide information about the possible biological relevance of the interactions between proteins and LPS, which may enhance or neutralize LPS-induced inflammatory responses. In this study, we designed and evaluated different types of ELISA that could be used to study possible interactions between LPS and any protein or peptide. We also analysed the usefulness and limitations of the different ELISAs. Specifically, we tested the capacity of several proteins and peptides to bind FITC-labeled LPSs from Escherichia coli serotypes O111:B4 and O55:B5 in an indirect ELISA and in two competitive ELISAs including casein hydrolysate (hCAS) and biotinylated polymyxin B (captured by deglycosylated avidin; PMX) as LPS-binding agents in the solid phase. We also examined the influence of pH, detergents and different blocking agents on LPS binding. Our results showed that the competitive hCAS-ELISA performed under mildly acidic conditions can be used as a general method for studying LPS interactions, while the more restrictive PMX-ELISA may help to identify proteins/peptides that are likely to have neutralizing properties in vitro or in vivo. PMID:27249227

Identification of a novel compound that inhibits iNOS and COX-2 expression in LPS-stimulated macrophages from Schisandra chinensis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, You Jin; Park, Sun Young; Kim, Sun Gun

2010-01-22

A novel {alpha}-iso-cubebenol, which has anti-inflammatory effects in lipopolysaccharide (LPS)-treated RAW 264.7 macrophages, was isolated from the fruits of Schisandra chinensis. {alpha}-iso-cubebenol inhibited LPS-induced nitric oxide (NO) and prostaglandin E{sub 2} (PGE{sub 2}) production. Consistent with these findings, {alpha}-iso-cubebenol also reduced the LPS-induced expression of inducible nitric oxide synthase and cyclooxygenase-2 at the protein and mRNA levels in a concentration-dependent manner. {alpha}-iso-cubebenol also inhibited LPS-induced nuclear translocation of the NF-{kappa}B p65 subunit. Furthermore, {alpha}-iso-cubebenol suppressed the phosphorylation of ERK, JNK, and p38 kinase induced by LPS. Since the novel {alpha}-iso-cubebenol blocked the production of several pro-inflammatory mediators induced by LPSmore » in macrophages, the molecule can be useful material for the development of anti-inflammatory agents against bacterial infections or endotoxin.« less

Therapeutic effects of silibinin on LPS-induced acute lung injury by inhibiting NLRP3 and NF-κB signaling pathways.

PubMed

Tian, Lin; Li, Weimin; Wang, Tan

2017-07-01

Silibinin, a natural product extracted from Silybum marianum (milk thistle), has been reported to have anti-inflammatory effect. The aim of this study was to explore the therapeutic effects and potential mechanisms of silibinin on lipopolysaccharide (LPS)-stimulated inflammatory responses in acute lung injury (ALI). Male BALB/c mice were conditioned with silibinin 1 h after intranasal instillation of LPS. After 12 h, the myeloperoxidase (MPO) level in lung tissues, the wet/dry (W/D) ratio, inflammatory cytokines in the bronchoalveolar lavage fluid (BALF), and histopathological examination of lung were detected. Our results showed that silibinin inhibited LPS-induced histopathological changes and MPO activity, as well as the wet/dry (W/D) ratio in the lung tissues. Furthermore, silibinin significantly inhibited LPS-induced inflammatory cytokines production in the BALF. In addition, silibinin suppressed LPS-induced NF-κB activation and the expression of NLRP3 inflammasome. These results indicate that silibinin exerts its anti-inflammatory effect by inhibiting NF-κB and NLRP3 signaling pathways. Copyright © 2017. Published by Elsevier Ltd.

Cyanidin-3-O-beta-glucoside inhibits LPS-induced expression of inflammatory mediators through decreasing IkappaBalpha phosphorylation in THP-1 cells.

PubMed

Zhang, Yinghui; Lian, Fuzhi; Zhu, Yanna; Xia, Min; Wang, Qing; Ling, Wenhua; Wang, Xiang-Dong

2010-09-01

As a common phytochemical, cyanidin 3-O-beta-glucoside (C3G) has a role in inhibiting inflammatory mediators; however, its mechanism of action remains unclear. The purpose of this study was to explore the effect of C3G on lipopolysaccharide (LPS)-stimulated TNFalpha and IL-6 expression in the human monocyte/macrophage cell line THP-1, and to explore the mechanisms involved. Differentiated THP-1 cells were treated with different concentrations of C3G (0.005, 0.05, 0.5,10 microM) in the absence or presence of 1 ng/mL LPS. mRNA expression levels were detected by real time PCR, and secretion of TNFalpha and IL-6, phosphorylated IkappaBalpha, and nuclear factor-kappa B (NF-kappaB) P65 were monitored by ELISA or Western blotting analysis. The role of an inhibitor of IkappaBalpha phosphorylation, BAY 11-7082, in C3G inhibition of LPS-induced cytokines expression was investigated. C3G (0.05-0.5 microM) treatment significantly inhibited LPS-stimulated TNFalpha and IL-6 mRNA expression and secretion of these proteins by THP-1 cells. Phosphorylation of IkappaBalpha and NF-kappaB nuclear translocation could be blocked by 0.5 microM C3G. BAY 11-7082 treatment abolished C3G-induced reduction of TNFalpha and IL-6. Our results suggest that C3G exerts its anti-inflammatory effect through inhibiting IkappaBalpha phosphorylation, thereby suppressing NF-kappaB activity in THP-1 cells.

Gypenoside XLIX, a naturally occurring gynosaponin, PPAR-alpha dependently inhibits LPS-induced tissue factor expression and activity in human THP-1 monocytic cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huang, Tom Hsun-Wei; Van Hoan Tran; Roufogalis, Basil D.

2007-01-01

Tissue factor (TF) is involved not only in the progression of atherosclerosis and other cardiovascular diseases, but is also associated with tumor growth, metastasis, and angiogenesis and hence may be an attractive target for directed cancer therapeutics. Gynostemma pentaphyllum (GP) is widely used in the treatment of various cardiovascular diseases including atherosclerosis, as well as cancers. Gypenoside (Gyp) XLIX, a dammarane-type glycoside, is one of the prominent components in GP. We have recently reported Gyp XLIX to be a potent peroxisome proliferator-activated receptor (PPAR)-alpha activator. Here we demonstrate that Gyp XLIX (0-300 {mu}M) concentration dependently inhibited TF promoter activity aftermore » induction by the inflammatory stimulus lipopolysaccharide (LPS) in human monocytic THP-1 cells transfected with promoter reporter constructs pTF-LUC. Furthermore, Gyp XLIX inhibited LPS-induced TF mRNA and protein overexpression in THP-1 monocyte cells. Its inhibition of LPS-induced TF hyperactivity was further confirmed by chromogenic enzyme activity assay. The activities of Gyp XLIX reported in this study were similar to those of Wy-14643, a potent synthetic PPAR-alpha activator. Furthermore, the Gyp XLIX-induced inhibitory effect on TF luciferase activity was completely abolished in the presence of the PPAR-alpha selective antagonist MK-886. The present findings suggest that Gyp XLIX inhibits LPS-induced TF overexpression and enhancement of its activity in human THP-1 monocytic cells via PPAR-alpha-dependent pathways. The data provide new insights into the basis of the use of the traditional Chinese herbal medicine G. pentaphyllum for the treatment of cardiovascular and inflammatory diseases, as well as cancers.« less

COX-2 contributes to LPS-induced Stat3 activation and IL-6 production in microglial cells

PubMed Central

Zhu, Jie; Li, Shuzhen; Zhang, Yue; Ding, Guixia; Zhu, Chunhua; Huang, Songming; Zhang, Aihua; Jia, Zhanjun; Li, Mei

2018-01-01

Many stimuli including lipopolysaccharide (LPS) could activate microglial cells to subsequently cause inflammatory nerve injury. However, the mechanism of LPS-induced neuroinflammation in microglial cells is still elusive. Thus, the present study was undertaken to examine the role of COX-2 in mediating the activation of Stat3 and the production of IL-6 in BV2 cells challenged with LPS. After 24 h treatment, LPS dose-dependently enhanced COX-2 expression at both mRNA and protein levels. Meanwhile, IL-6 with other inflammatory cytokines including IL-1β, TNF-α, and MCP-1 were similarly enhanced by LPS. Then a specific COX-2 inhibitor (NS-398) was administered to BV2 before LPS treatment. Significantly, COX-2 inhibition suppressed the upregulation of IL-6 at both mRNA and protein levels in line with the trend blockade on IL-1β, TNF-α, and MCP-1. Stat3 drives proinflammatory signaling pathways and contributes to IL-6 production via a transcriptional mechanism in many diseases. Here we found that inhibition of COX-2 entirely blocked LPS-induced Stat3 phosphorylation, which might contribute to the blockade of IL-6 production to some extent. Meanwhile, COX-2 siRNA approach largely reproduced the phenotypes shown by specific COX-2 inhibitor in LPS-treated BV2 cells. Together, these findings suggested that COX-2 might contribute to LPS-induced IL-6 production possibly through activating Stat3 signaling pathway in microglial cells. PMID:29636886

Soluble β-(1,3)-glucans enhance LPS-induced response in the monocyte activation test, but inhibit LPS-mediated febrile response in rabbits: Implications for pyrogenicity tests.

PubMed

Pardo-Ruiz, Zenia; Menéndez-Sardiñas, Dalia E; Pacios-Michelena, Anabel; Gabilondo-Ramírez, Tatiana; Montero-Alejo, Vivian; Perdomo-Morales, Rolando

2016-01-01

In the present study, we aimed to determine the influence of β-(1,3)-d-glucans on the LPS-induced pro-inflammatory cytokine response in the Monocyte Activation Test (MAT) for pyrogens, and on the LPS-induced febrile response in the Rabbit Pyrogen Test (RPT), thus evaluating the resulting effect in the outcome of each test. It was found that β-(1,3)-d-glucans elicited the production of pro-inflammatory cytokines IL-1β, IL-6 and TNF-α, also known as endogenous pyrogens, but not enough to classify them as pyrogenic according to MAT. The same β-(1,3)-d-glucans samples were non-pyrogenic by RPT. However, β-(1,3)-d-glucans significantly enhanced the LPS-induced pro-inflammatory cytokines response in MAT, insomuch that samples containing non-pyrogenic concentrations of LPS become pyrogenic. On the other hand, β-(1,3)-d-glucans had no effect on sub-pyrogenic LPS doses in the RPT, but surprisingly, inhibited the LPS-induced febrile response of pyrogenic LPS concentrations. Thus, while β-(1,3)-d-glucans could mask the LPS pyrogenic activity in the RPT, they exerted an overstimulation of pro-inflammatory cytokines in the MAT. Hence, MAT provides higher safety since it evidences an unwanted biological response, which is not completely controlled and is overlooked by the RPT. Copyright © 2015 Elsevier B.V. All rights reserved.

A central role for the mammalian target of rapamycin in LPS-induced anorexia in mice.

PubMed

Yue, Yunshuang; Wang, Yi; Li, Dan; Song, Zhigang; Jiao, Hongchao; Lin, Hai

2015-01-01

Bacterial lipopolysaccharide (LPS), also known as endotoxin, induces profound anorexia. However, the LPS-provoked pro-inflammatory signaling cascades and the neural mechanisms underlying the development of anorexia are not clear. Mammalian target of rapamycin (mTOR) is a key regulator of metabolism, cell growth, and protein synthesis. This study aimed to determine whether the mTOR pathway is involved in LPS-induced anorexia. Effects of LPS on hypothalamic gene/protein expression in mice were measured by RT-PCR or western blotting analysis. To determine whether inhibition of mTOR signaling could attenuate LPS-induced anorexia, we administered an i.c.v. injection of rapamycin, an mTOR inhibitor, on LPS-treated male mice. In this study, we showed that LPS stimulates the mTOR signaling pathway through the enhanced phosphorylation of mTOR(Ser2448) and p70S6K(Thr389). We also showed that LPS administration increased the phosphorylation of FOXO1(Ser256), the p65 subunit of nuclear factor kappa B (P<0.05), and FOXO1/3a(Thr) (24) (/) (32) (P<0.01). Blocking the mTOR pathway significantly attenuated the LPS-induced anorexia by decreasing the phosphorylation of p70S6K(Thr389), FOXO1(Ser256), and FOXO1/3a(Thr) (24) (/) (32). These results suggest promising approaches for the prevention and treatment of LPS-induced anorexia. © 2015 Society for Endocrinology.

Lignans from Arctium lappa and their inhibition of LPS-induced nitric oxide production.

PubMed

Park, So Young; Hong, Seong Su; Han, Xiang Hua; Hwang, Ji Sang; Lee, Dongho; Ro, Jai Seup; Hwang, Bang Yeon

2007-01-01

A new butyrolactone sesquilignan, isolappaol C (1), together with four known lignans, lappaol C (2), lappaol D (3), lappaol F (4), and diarctigenin (5), were isolated from the methanolic extract of the seeds from the Arctium lappa plant. The structure of isolappaol C (1) was determined by spectral analysis including 1D- and 2D-NMR. All the isolates were evaluated for their inhibitory effects on the LPS-induced nitric oxide production using murine macrophage RAW264.7 cells. Lappaol F (4) and diarctigenin (5) strongly inhibited NO production in the LPS-stimulated RAW264.7 cells with IC(50) values of 9.5 and 9.6 microM, respectively.

The pharmacological efficacy of the anti-IL17 scFv and sTNFR1 bispecific fusion protein in inflammation mouse stimulated by LPS.

PubMed

Yang, Yongbi; Zhang, Teng; Cao, Hongxue; Yu, Dan; Zhang, Tong; Zhao, Shaojuan; Jing, Xiaohui; Song, Liying; Liu, Yunye; Che, Ruixiang; Liu, Xin; Li, Deshan; Ren, Guiping

2017-08-01

Acute lung injury (ALI) is still a leading cause of morbidity and mortality in critically ill patients. Recently, our study found that a bispecific fusion protein treatment can ameliorate the lung injury induced by LPS. However, the molecular mechanisms which bispecific fusion protein ameliorates acute lung injury remain unclear. In this study, we found that the bispecific fusion protein treatment inhibited the nuclear transcription of NF-κB in confocal laser scanning fluorescence microscopy, the bispecific fusion protein exert protective effects in the cell model of ALI induced by lipopolysaccharide (LPS) via inhibiting the nuclear factor κB (NF-κB) signaling pathway and mediate inflammation. Moreover, the treatment of the bispecific fusion protein show its efficacy in animal models stimulated by LPS, the results of real-time PCR and ELISA demonstrate that bispecific fusion protein treatment effectively inhibited the over-expression of inflammatory cytokines(tumor necrosis factor α, interleukin 1β and interleukin 17). In addition, LPS-challenged mice exhibited significant lung injury characterized by the deterioration of histopathology, which was meliorated by bispecific fusion protein treatment. Collectively, these results demonstrate that bispecific fusion protein treatment ameliorates LPS-induced ALI through reducing inflammatory cytokines and lung inflammation, which may be associated with the decreased the nuclear transcription of NF-κB. The bispecific fusion protein may be useful as a novel therapy to treat ALI. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Basolateral LPS inhibits NHE3 and HCO3− absorption through TLR4/MyD88-dependent ERK activation in medullary thick ascending limb

PubMed Central

Watts, Bruns A.; George, Thampi; Sherwood, Edward R.

2011-01-01

Sepsis is associated with defects in renal tubule function, but the underlying mechanisms are incompletely understood. Recently, we demonstrated that Gram-negative bacterial lipopolysaccharide (LPS) inhibits HCO3− absorption in the medullary thick ascending limb (MTAL) through activation of Toll-like receptor 4 (TLR4). Here, we examined the mechanisms responsible for inhibition of HCO3− absorption by basolateral LPS. Adding LPS to the bath decreased HCO3− absorption by 30% in rat and mouse MTALs perfused in vitro. The inhibition of HCO3− absorption was eliminated by the mitogen-activated protein kinase/extracellular signal-regulated kinase (MEK)/ERK inhibitors U0126 and PD98059. LPS induced a rapid (<15 min) and sustained (up to 60 min) increase in ERK phosphorylation in microdissected MTALs that was blocked by PD98059. The effects of basolateral LPS to activate ERK and inhibit HCO3− absorption were eliminated in MTALs from TLR4−/− and myeloid differentiation factor 88 (MyD88)−/− mice but were preserved in MTALs from TIR (Toll/interleukin-1 receptor) domain-containing adapter-inducing interferon-β (Trif)−/− mice. Basolateral LPS decreased apical Na+/H+ exchanger 3 NHE3 activity through a decrease in maximal velocity (Vmax). The inhibition of NHE3 by LPS was eliminated by MEK/ERK inhibitors. LPS inhibited HCO3− absorption despite the presence of physiological stimuli that activate ERK in the MTAL. We conclude that basolateral LPS inhibits HCO3− absorption in the MTAL through activation of a TLR4/MyD88/MEK/ERK pathway coupled to inhibition of NHE3. These studies identify NHE3 as a target of TLR4 signaling in the MTAL and show that bacterial molecules can impair the absorptive functions of renal tubules through inhibition of this exchanger. The ERK pathway links TLR4 to downstream modulation of ion transport proteins and represents a potential target for treatment of sepsis-induced renal tubule dysfunction. PMID:21881005

Activation of MTOR in pulmonary epithelium promotes LPS-induced acute lung injury.

PubMed

Hu, Yue; Lou, Jian; Mao, Yuan-Yuan; Lai, Tian-Wen; Liu, Li-Yao; Zhu, Chen; Zhang, Chao; Liu, Juan; Li, Yu-Yan; Zhang, Fan; Li, Wen; Ying, Song-Min; Chen, Zhi-Hua; Shen, Hua-Hao

2016-12-01

MTOR (mechanistic target of rapamycin [serine/threonine kinase]) plays a crucial role in many major cellular processes including metabolism, proliferation and macroautophagy/autophagy induction, and is also implicated in a growing number of proliferative and metabolic diseases. Both MTOR and autophagy have been suggested to be involved in lung disorders, however, little is known about the role of MTOR and autophagy in pulmonary epithelium in the context of acute lung injury (ALI). In the present study, we observed that lipopolysaccharide (LPS) stimulation induced MTOR phosphorylation and decreased the expression of MAP1LC3B/LC3B (microtubule-associated protein 1 light chain 3 β)-II, a hallmark of autophagy, in mouse lung epithelium and in human bronchial epithelial (HBE) cells. The activation of MTOR in HBE cells was mediated by TLR4 (toll-like receptor 4) signaling. Genetic knockdown of MTOR or overexpression of autophagy-related proteins significantly attenuated, whereas inhibition of autophagy further augmented, LPS-induced expression of IL6 (interleukin 6) and IL8, through NFKB signaling in HBE cells. Mice with specific knockdown of Mtor in bronchial or alveolar epithelial cells exhibited significantly attenuated airway inflammation, barrier disruption, and lung edema, and displayed prolonged survival in response to LPS exposure. Taken together, our results demonstrate that activation of MTOR in the epithelium promotes LPS-induced ALI, likely through downregulation of autophagy and the subsequent activation of NFKB. Thus, inhibition of MTOR in pulmonary epithelial cells may represent a novel therapeutic strategy for preventing ALI induced by certain bacteria.

Inhibition of nuclear factor-κB signal by pyrrolidine dithiocarbamate alleviates lipopolysaccharide-induced acute lung injury

PubMed Central

Yang, Hongfu; Sun, Rongqing; Ma, Ning; Liu, Qilong; Sun, Xiaoge; Zi, Panpan; Wang, Junsheng; Chao, Ke; Yu, Lei

2017-01-01

This study mainly studied the effect of inhibition of nuclear factor-κB (NF-κB) signal by pyrrolidine dithiocarbamate (PDTC) on lipopolysaccharide (LPS)-induced inflammatory response, oxidative stress, and mitochondrial dysfunction in a murine acute lung injury model. The results showed that LPS exposure activated NF-κB and its upstream proteins and caused lung inflammation, oxidative stress, and mitochondrial dysfunction in mice. While inhibition of NF-κB by PDTC adminstration alleviated LPS-induced generation of lymphocytes, IL-1β, and TNF-α. Malondialdehyde, a common oxidative product, was markedly reduced after PDTC treatment in LPS-challenged mice. Furthermore, PDTC alleviated LPS-induced mitochondrial dysfunction via improving ATP synthesis and uncoupling protein 2 expression. In conclusion, inhibition of NF-κB by PDTC alleviated LPS-induced acute lung injury via maintaining inflammatory status, oxidative balance, and mitochondrial function in mice. PMID:28521300

Wheatgrass-Derived Polysaccharide Has Antiinflammatory, Anti-Oxidative and Anti-Apoptotic Effects on LPS-Induced Hepatic Injury in Mice.

PubMed

Nepali, Sarmila; Ki, Hyeon-Hui; Lee, Ji-Hyun; Lee, Hoon-Yeon; Kim, Dae-Ki; Lee, Young-Mi

2017-07-01

Hepatic injury occurs frequently during sepsis, and polysaccharides isolated from plants have been reported to have antiinflammatory and antioxidant effects in various models. However, the effect of wheatgrass-derived polysaccharide (WGP) has not been previously studied. In the present study, we investigated the effect of WGP on lipopolysaccharide (LPS)-induced hepatic injury in mice. Mice were pre-treated with WGP (100 or 200 mg/kg daily for 2 days) and then challenged with LPS (1 mg/kg, intraperitoneal), and sacrificed after 12 h. Wheatgrass-derived polysaccharide decreased serum aminotransferase levels and histological changes as compared with LPS-challenged mice. Wheatgrass-derived polysaccharide also significantly inhibited LPS-induced pro-inflammatory cytokine up-regulation and improved the oxidative status of liver tissues. Furthermore, these effects were found to be mediated by the suppression of the transcriptional activity of nuclear factor-kappa B (NF-κB), due to inhibitions of transforming growth factor beta (TGF-β)-activated kinase (TAK)-1 phosphorylation and inhibition of kappa B (IκB)-α degradation. In addition, WGP inhibited the activations of mitogen-activated protein kinases (MAPKs). Wheatgrass-derived polysaccharide also attenuated hepatic cell death by modulating caspase-3 and apoptosis associated mitochondrial proteins, such as, B-cell lymphoma 2 (Bcl-2) and Bcl-2-associated X (Bax). Taken together, WGP possesses antiinflammatory, anti-oxidant and anti-apoptotic activity and ameliorates LPS-induced liver injury in mice. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

6-Shogaol attenuates LPS-induced inflammation in BV2 microglia cells by activating PPAR-γ.

PubMed

Han, Qinghe; Yuan, Qinghai; Meng, Xiaolin; Huo, Junyuan; Bao, Yuxin; Xie, Guanghong

2017-06-27

6-Shogaol, a pungent agent isolated from Zingiber officinale Roscoe, has been known to have anti-tumor and anti-inflammatory effects. However, the anti-inflammatory effects and biological mechanism of 6-Shogaol in LPS-activated BV2 microglia remains largely unknown. In this study, we evaluated the anti-inflammatory effects of 6-Shogaol in LPS-activated BV2 microglia. 6-Shogaol was administrated 1 h before LPS treatment. The production of inflammatory mediators were detected by ELISA. The expression of NF-κB and PPAR-γ were detected by western blot analysis. Our results revealed that 6-Shogaol inhibited LPS-induced TNF-α, IL-1β, IL-6, and PGE2 production in a concentration dependent manner. Furthermore, 6-Shogaol inhibited LPS-induced NF-κB activation by inhibiting phosphorylation and nuclear translocation of NF-κB p65. In addition, 6-Shogaol could increase the expression of PPAR-γ. Moreover, inhibition of PPAR-γ by GW9662 could prevent the inhibition of 6-Shogaol on LPS-induced inflammatory mediator production. In conclusion, 6-Shogaol inhibits LPS-induced inflammation by activating PPAR-γ.

Akt mediates 17beta-estradiol and/or estrogen receptor-alpha inhibition of LPS-induced tumor necresis factor-alpha expression and myocardial cell apoptosis by suppressing the JNK1/2-NFkappaB pathway.

PubMed

Liu, Chung-Jung; Lo, Jeng-Fan; Kuo, Chia-Hua; Chu, Chun-Hsien; Chen, Li-Ming; Tsai, Fuu-Jen; Tsai, Chang-Hai; Tzang, Bor-Show; Kuo, Wei-Wen; Huang, Chih-Yang

2009-09-01

Evidence shows that women have lower tumour necrosis factor-alpha (TNF-alpha) levels and lower incidences of heart dysfunction and sepsis-related morbidity and mortality. To identify the cardioprotective effects and precise cellular/molecular mechanisms behind estrogen and estrogen receptors (ERs), we investigated the effects of 17beta-estradiol (E(2)) and estrogen receptor alpha (ERalpha) on LPS-induced apoptosis by analyzing the activation of survival and death signalling pathways in doxycycline (Dox)-inducible Tet-On/ERalpha H9c2 myocardial cells and ERalpha-transfected primary cardiomyocytes overexpressing ERalpha. We found that LPS challenge activated JNK1/2, and then induced IkappaB degradation, NFkappaB activation, TNF-alpha up-regulation and subsequent myocardial apoptotic responses. In addition, treatments involving E(2), membrane-impermeable BSA-E(2) and/or Dox, which induces ERalpha overexpression, significantly inhibited LPS-induced apoptosis by suppressing LPS-up-regulated JNK1/2 activity, IkappaB degradation, NFkappaB activation and pro-apoptotic proteins (e.g. TNF-alpha, active caspases-8, t-Bid, Bax, released cytochrome c, active caspase-9, active caspase-3) in myocardial cells. However, the cardioprotective properties of E(2), BSA-E(2) and ERalpha overexpression to inhibit LPS-induced apoptosis and promote cell survival were attenuated by applying LY294002 (PI3K inhibitor) and PI3K siRNA. These findings suggest that E(2), BSA-E(2) and ERalpha expression exert their cardioprotective effects by inhibiting JNK1/2-mediated LPS-induced TNF-alpha expression and cardiomyocyte apoptosis through activation of Akt.

[Gallic acid inhibits inflammatory response of RAW264.7 macrophages by blocking the activation of TLR4/NF-κB induced by LPS].

PubMed

Huang, Lihua; Hou, Lin; Xue, Hainan; Wang, Chunjie

2016-12-01

Objective To observe the influence of gallic acid on Toll-like receptor 4/nuclear factor-κB (TLR4/NF-κB) pathway in the RAW264.7 macrophages stimulated by lipopolysaccharide (LPS). Methods RAW264.7 macrophages were divided into the following groups: control group, LPS group, LPS combined with gallic acid group, LPS combined with pyrrolidine dithiocarbamate (PDTC) group and LPS combined with dexamethasone (DM) group. RAW264.7 cells were cultured for 24 hours after corresponding treatments. The levels of tumor necrosis factor α (TNF-α), interleukin-1 (IL-1) and IL-6 were detected by ELISA. The levels of TLR4 and NF-κB mRNAs were tested by real-time PCR. The levels of p-IκBα, p65, p-p65 and TLR4 proteins were examined by Western blotting. Results The expression levels of TNF-α, IL-1 and IL-6 were up-regulated in the RAW264.7 macrophages after stimulated by LPS. Gallic acid could reduce the elevated expression levels of TNF-α, IL-1 and IL-6 induced by LPS. The expression of TLR4 significantly increased after stimulated by LPS and NF-κB was activated. Gallic acid could reverse the above changes and prevent the activation of NF-κB. Conclusion Gallic acid could inhibit LPS-induced inflammatory response in RAW264.7 macrophages via TLR4/NF-κB pathway.

Irisin-mediated protective effect on LPS-induced acute lung injury via suppressing inflammation and apoptosis of alveolar epithelial cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shao, Lei; Jinan Central Hospital Affiliated to Shandong University, Jinan 250012; Meng, Di

It is considered that the essence of acute lung injury (ALI) is an excessive and uncontrolled inflammatory response in lung, of which mainly is attributed to the release of inflammatory mediators. Recent studies demonstrated that irisin, which is a metabolism associated factor after physical exercise could suppression of inflammation by regulating cellular signaling pathways, however, the underlying molecular mechanism remains to be determined. The present study aimed to reveal the potential mechanism responsible for the anti-inflammatory effects of irisin on LPS-induced acute lung injury in mice and in A549 cells. The results of histopathological changes showed that irisin ameliorated the lungmore » injury that was induced by LPS in time- and dose-dependent manner. QRT-PCR assays demonstrated that irisin suppressed the production of IL-1β, IL-6, MCP-1 and TNF-α, and western blot assays demonstrated that irisin suppressed apoptosis of ALI. The expression of caspase-3 and Bax were decreased and Bcl-2 was increased by irisin administration. Further study was conducted on nuclear factor (NF)-κB and mitogen-activated protein kinase (MAPK) using pathways using western blots. The results showed that irisin inhibited reduced LPS-induced activation of MAPK and NF-κB signaling. All results indicated that irisin has protective effect on LPS-induced ALI in mice and in A549 cells. Thus, irisn related with physical exercise may be a potential therapy for the treatment of pulmonary inflammation. - Highlights: • Irisin inhibited the inflammation reactivity of cells and pathological changes of LPS-induced lung injury in mice. • Irisin inhibited mRNA expression of inflammatory cytokines induced by LPS in A549 cells. • Irisin inhibited apoptosis induced by LPS in the injured lung. • Irisin reduced LPS-induced activation of MAPK and NF-κB signaling pathways.« less

6-Shogaol attenuates LPS-induced inflammation in BV2 microglia cells by activating PPAR-γ

PubMed Central

Han, Qinghe; Yuan, Qinghai; Meng, Xiaolin; Huo, Junyuan; Bao, Yuxin; Xie, Guanghong

2017-01-01

6-Shogaol, a pungent agent isolated from Zingiber officinale Roscoe, has been known to have anti-tumor and anti-inflammatory effects. However, the anti-inflammatory effects and biological mechanism of 6-Shogaol in LPS-activated BV2 microglia remains largely unknown. In this study, we evaluated the anti-inflammatory effects of 6-Shogaol in LPS-activated BV2 microglia. 6-Shogaol was administrated 1 h before LPS treatment. The production of inflammatory mediators were detected by ELISA. The expression of NF-κB and PPAR-γ were detected by western blot analysis. Our results revealed that 6-Shogaol inhibited LPS-induced TNF-α, IL-1β, IL-6, and PGE2 production in a concentration dependent manner. Furthermore, 6-Shogaol inhibited LPS-induced NF-κB activation by inhibiting phosphorylation and nuclear translocation of NF-κB p65. In addition, 6-Shogaol could increase the expression of PPAR-γ. Moreover, inhibition of PPAR-γ by GW9662 could prevent the inhibition of 6-Shogaol on LPS-induced inflammatory mediator production. In conclusion, 6-Shogaol inhibits LPS-induced inflammation by activating PPAR-γ. PMID:28410218

Eupatolide inhibits lipopolysaccharide-induced COX-2 and iNOS expression in RAW264.7 cells by inducing proteasomal degradation of TRAF6.

PubMed

Lee, Jongkyu; Tae, Nara; Lee, Jung Joon; Kim, Taeho; Lee, Jeong-Hyung

2010-06-25

Inula britannica is a traditional medicinal plant used to treat bronchitis, digestive disorders, and inflammation in Eastern Asia. Here, we identified eupatolide, a sesquiterpene lactone from I. britannica, as an inhibitor of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) expression. Eupatolide inhibited the production of nitric oxide (NO) and prostaglandin E(2) (PGE(2)) as well as iNOS and COX-2 protein expression in lipopolysaccharide (LPS)-stimulated RAW264.7 cells. Eupatolide dose-dependently decreased the mRNA levels and the promoter activities of COX-2 and iNOS in LPS-stimulated RAW264.7 cells. Moreover, eupatolide significantly suppressed the LPS-induced expression of nuclear factor-kappa B (NF-kappaB) and activator protein-1 (AP-1) reporter genes. Pretreatment of eupatolide inhibited LPS-induced phosphorylation and degradation of I kappaB alpha, and phosphorylation of RelA/p65 on Ser-536 as well as the activation of mitogen-activated protein kinases (MAPKs) and Akt in LPS-stimulated RAW264.7 cells. Eupatolide induced proteasomal degradation of tumor necrosis factor receptor-associated factor-6 (TRAF6), and subsequently inhibited LPS-induced TRAF6 polyubiquitination. These results suggest that eupatolide blocks LPS-induced COX-2 and iNOS expression at the transcriptional level through inhibiting the signaling pathways such as NF-kappaB and MAPKs via proteasomal degradation of TRAF6. Taken together, eupatolide may be a novel anti-inflammatory agent that induces proteasomal degradation of TRAF6, and a valuable compound for modulating inflammatory conditions. (c) 2010 Elsevier B.V. All rights reserved.

Morin hydrate augments phagocytosis mechanism and inhibits LPS induced autophagic signaling in murine macrophage.

PubMed

Jakhar, Rekha; Paul, Souren; Chauhan, Anil Kumar; Kang, Sun Chul

2014-10-01

Morin, a natural flavonoid that is the primary bioactive constituent of the family Moraceae, has been found to be associated with many therapeutic properties. In this study, we evaluated the immunomodulatory activities of increasing concentration of morin hydrate in vitro. Three different concentrations of morin hydrate (5, 10, and 15μM) were used to evaluate their effect on splenocyte proliferation, phagocytic activity of macrophages, cytokine secretion and complement inhibition. We also evaluated the role of morin hydrate on lipopolysaccharide (LPS) induced autophagy. Our study demonstrated that morin hydrate elicited a significant increase in splenocyte proliferation, phagocytic capacity and suppressed the production of cytokines and nitric oxide in activated macrophages. Humoral immunity measured by anti-complement activity showed an increase in inhibition of the complement system after the addition of morin hydrate, where morin hydrate at 15μM concentration induced a significant inhibition. Depending on our results, we can also conclude that morin hydrate protects macrophages from LPS induced autophagic cell death. Our findings suggest that morin hydrate represents a structurally diverse class of flavonoid and this structural variability can profoundly affect its cell-type specificity and its biological activities. Supplementation of immune cells with morin hydrate has an upregulating and immunoprotective effect that shows potential as a countermeasure to the immune dysfunction and suggests an interesting use in inflammation related diseases. Copyright © 2014 Elsevier B.V. All rights reserved.

LPS-induced inflammatory response triggers cell cycle reactivation in murine neuronal cells through retinoblastoma proteins induction.

PubMed

D'Angelo, Barbara; Astarita, Carlo; Boffo, Silvia; Massaro-Giordano, Mina; Antonella Ianuzzi, Carmelina; Caporaso, Antonella; Macaluso, Marcella; Giordano, Antonio

2017-01-01

Cell cycle reactivation in adult neurons is an early hallmark of neurodegeneration. The lipopolysaccharide (LPS) is a well-known pro-inflammatory factor that provokes neuronal cell death via glial cells activation. The retinoblastoma (RB) family includes RB1/p105, retinoblastoma-like 1 (RBL1/p107), and retinoblastoma-like 2 (Rb2/p130). Several studies have indicated that RB proteins exhibit tumor suppressor activities, and play a central role in cell cycle regulation. In this study, we assessed LPS-mediated inflammatory effect on cell cycle reactivation and apoptosis of neuronally differentiated cells. Also, we investigated whether the LPS-mediated inflammatory response can influence the function and expression of RB proteins. Our results showed that LPS challenges triggered cell cycle reactivation of differentiated neuronal cells, indicated by an accumulation of cells in S and G2/M phase. Furthermore, we found that LPS treatment also induced apoptotic death of neurons. Interestingly, we observed that LPS-mediated inflammatory effect on cell cycle re-entry and apoptosis was concomitant with the aberrant expression of RBL1/p107 and RB1/p105. To the best of our knowledge, our study is the first to indicate a role of LPS in inducing cell cycle re-entry and/or apoptosis of differentiated neuronal cells, perhaps through mechanisms altering the expression of specific members of RB family proteins. This study provides novel information on the biology of post-mitotic neurons and could help in identifying novel therapeutic targets to prevent de novo cell cycle reactivation and/or apoptosis of neurons undergoing neurodegenerative processes.

Inhibition of endogenous heat shock protein 70 attenuates inducible nitric oxide synthase induction via disruption of heat shock protein 70/Na(+) /H(+) exchanger 1-Ca(2+) -calcium-calmodulin-dependent protein kinase II/transforming growth factor β-activated kinase 1-nuclear factor-κB signals in BV-2 microglia.

PubMed

Huang, Chao; Lu, Xu; Wang, Jia; Tong, Lijuan; Jiang, Bo; Zhang, Wei

2015-08-01

Inducible nitric oxide synthase (iNOS) critically contributes to inflammation and host defense. The inhibition of heat shock protein 70 (Hsp70) prevents iNOS induction in lipopolysaccharide (LPS)-stimulated macrophages. However, the role and mechanism of endogenous Hsp70 in iNOS induction in microglia remains unclear. This study addresses this issue in BV-2 microglia, showing that Hsp70 inhibition or knockdown prevents LPS-induced iNOS protein expression and nitric oxide production. Real-time PCR experiments showed that LPS-induced iNOS mRNA transcription was blocked by Hsp70 inhibition. Further studies revealed that the inhibition of Hsp70 attenuated LPS-stimulated nuclear translocation and phosphorylation of nuclear factor (NF)-κB as well as the degradation of inhibitor of κB (IκB)-α and phosphorylation of IκB kinase β (IKKβ). This prevention effect of Hsp70 inhibition on IKKβ-NF-κB activation was found to be dependent on the Ca(2+) /calcium-calmodulin-dependent protein kinase II (CaMKII)/transforming growth factor β-activated kinase 1 (TAK1) signals based on the following observations: 1) chelation of intracellular Ca(2+) or inhibition of CaMKII reduced LPS-induced increases in TAK1 phosphorylation and 2) Hsp70 inhibition reduced LPS-induced increases in CaMKII/TAK1 phosphorylation, intracellular pH value, [Ca(2+) ]i , and CaMKII/TAK1 association. Mechanistic studies showed that Hsp70 inhibition disrupted the association between Hsp70 and Na(+) /H(+) exchanger 1 (NHE1), which is an important exchanger responsible for Ca(2+) influx in LPS-stimulated cells. These studies demonstrate that the inhibition of endogenous Hsp70 attenuates the induction of iNOS, which likely occurs through the disruption of NHE1/Hsp70-Ca(2+) -CaMKII/TAK1-NF-κB signals in BV-2 microglia, providing further insight into the functions of Hsp70 in the CNS. © 2015 Wiley Periodicals, Inc.

The anti-inflammatory effect of TR6 on LPS-induced mastitis in mice.

PubMed

Hu, Xiaoyu; Fu, Yunhe; Tian, Yuan; Zhang, Zecai; Zhang, Wenlong; Gao, Xuejiao; Lu, Xiaojie; Cao, Yongguo; Zhang, Naisheng

2016-01-01

[TRIAP]-derived decoy peptides have anti-inflammatory properties. In this study, we synthesized a TRIAP-derived decoy peptide (TR6) containing, the N-terminal portion of the third helical region of the [TIRAP] TIR domain (sequence "N"-RQIKIWFQNRRMKWK and -KPGFLRDPWCKYQML-"C"). We evaluated the effects of TR6 on lipopolysaccharide-induced mastitis in mice. In vivo, the mastitis model was induced by LPS administration for 24h, and TR6 treatment was initiated 1h before or after induction of LPS. In vitro, primary mouse mammary epithelial cells and neutrophils were used to investigate the effects of TR6 on LPS-induced inflammatory responses. The results showed that TR6 significantly inhibited mammary gland hisopathologic changes, MPO activity, and LPS-induced production of TNF-α, IL-1β and IL-6. In vitro, TR6 significantly inhibited LPS-induced TNF-α and IL-6 production and phosphorylation of NF-κB and MAPKs. In conclusion, this study demonstrated that the anti-inflammatory effect of TR6 against LPS-induced mastitis may be due to its ability to inhibit TLR4-mediated NF-κB and MAPK signaling pathways. TR6 may be a promising therapeutic reagent for mastitis treatment. Copyright © 2015. Published by Elsevier B.V.

Inhibition of RANKL- and LPS-induced osteoclast differentiations by novel NF-κB inhibitor DTCM-glutarimide.

PubMed

Koide, Naoki; Kaneda, Ayumi; Yokochi, Takashi; Umezawa, Kazuo

2015-03-01

We have isolated 9-methylstreptimidone from microorganism as a new NF-κB inhibitor. Later, we designed 3-[(dodecylthiocarbonyl) methyl]-glutarimide (DTCM-glutarimide) as an analog of this compound, which shows anti-inflammatory activity in vivo. In the present research, we found that DTCM-glutarimide inhibited receptor activator of nuclear factor-κB ligand (RANKL)-induced osteoclast differentiation of mouse bone marrow-derived macrophages and RANKL- or lipopolysaccharide (LPS)-induced osteoclast differentiation of RAW 264.7 cells without any toxicity. It also inhibited the RANKL-induced NFATc1 expression. Upstream signaling involving phosphorylation of Akt and GSK-3β was induced by RANKL, of which the signaling was inhibited by DTCM-glutarimide. Then DTCM-glutarimide was confirmed to inhibit RANKL-induced NF-κB activity, possibly by inhibiting the Akt-mediated activation of IKK. Thus, DTCM-glutarimide inhibited osteoclastogenesis by blocking both the Akt-GSK3β-NFATc1 and NF-κB-NFATc1 pathways. DTCM-glutarimide may be a candidate as a chemotherapeutic agent for severe bone resorption diseases. Copyright © 2015 Elsevier B.V. All rights reserved.

Anti-inflammatory effect of procyanidins from wild grape (Vitis amurensis) seeds in LPS-induced RAW 264.7 cells.

PubMed

Bak, Min-Ji; Truong, Van Long; Kang, Hey-Sook; Jun, Mira; Jeong, Woo-Sik

2013-01-01

In the present study, the anti-inflammatory effect and underlying mechanisms of wild grape seeds procyanidins (WGP) were examined using lipopolysaccharide- (LPS-) stimulated RAW 264.7 cells. We used nitric oxide (NO) and prostaglandin E2 (PGE2) and reactive oxygen species (ROS) assays to examine inhibitory effect of WGP and further investigated the mechanisms of WGP suppressed LPS-mediated genes and upstream expression by Western blot and confocal microscopy analysis. Our data indicate that WGP significantly reduced NO, PGE2, and ROS production and also inhibited the expression of proinflammatory mediators such as inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) protein expressions. Consistently, WGP significantly reduced LPS-stimulated expression of proinflammatory cytokines such as tumor necrosis factor α (TNF-α) and interleukin- (IL-) 1 β . Moreover, WGP prevented nuclear translocation of nuclear factor- κ B (NF κ B) p65 subunit by reducing inhibitory κ B- α (I κ B α) and NF κ B phosphorylation. Furthermore, we found that WGP inhibited LPS-induced phosphorylation of p38 mitogen-activated protein kinase (MAPK). Taken together, our results demonstrated that WGP exerts potent anti-inflammatory activity through the inhibition of iNOS and COX-2 by regulating NF κ B and p38 MAPK pathway.

Naloxone inhibits nod-like receptor protein 3 inflammasome.

PubMed

Lin, Han-Yu; Chang, Ya-Ying; Kao, Ming-Chang; Huang, Chun-Jen

2017-11-01

Naloxone, an opioid receptor antagonist, possesses potent anti-inflammation effects. We previously confirmed the effects of naloxone on inhibiting upregulation of inflammatory cytokine interleukin-1β (IL-1β). Production of mature form IL-1β is mediated by the nod-like receptor protein 3 (NLRP3) inflammasome, a multiprotein complex composed of NLRP3, and the adaptor protein apoptosis-associated speck-like protein contains a caspase recruitment domain (ASC). We elucidated whether naloxone could inhibit the activation of NLRP3 inflammasome. To induce IL-1β production and NLRP3 inflammasome activation, the human monocytic leukemia cell line THP-1 cells were first primed with lipopolysaccharide (LPS, 1 μg/mL) and then activated with adenosine triphosphate (ATP, 1 mM). For NLRP3 transcription, THP-1 cells were only treated with LPS priming. Enzyme-link immunosorbent assay data revealed that the concentration of IL-1β in THP-1 cells treated with LPS plus ATP was significantly higher than that in THP-1 cells treated with LPS plus ATP plus naloxone (0.1 μM) (P < 0.001). Real-time quantitative reverse transcription and polymerase chain reaction data also revealed that NLRP3 mRNA concentration in THP-1 cells treated with LPS was significantly higher than that in THP-1 cells treated with LPS plus naloxone (P = 0.001). ASC speck formation, that is, ASC assembles into a large protein complex, is an indicator for NLRP3 inflammasome activation. Our data revealed that the percentage of cells containing ASC specks in THP-1 cells treated with LPS plus ATP was also significantly higher than that in THP-1 cells treated with LPS plus ATP plus naloxone (P < 0.001). Naloxone inhibits NLRP3 inflammasome activation. Copyright © 2017 Elsevier Inc. All rights reserved.

Liver X receptor agonist prevents LPS-induced mastitis in mice.

PubMed

Fu, Yunhe; Tian, Yuan; Wei, Zhengkai; Liu, Hui; Song, Xiaojing; Liu, Wenbo; Zhang, Wenlong; Wang, Wei; Cao, Yongguo; Zhang, Naisheng

2014-10-01

Liver X receptor-α (LXR-α) which belongs to the nuclear receptor superfamily, is a ligand-activated transcription factor. Best known for its ability to regulate lipid metabolism and transport, LXRs have recently also been implicated in regulation of inflammatory response. The aim of this study was to investigate the preventive effects of synthetic LXR-α agonist T0901317 on LPS-induced mastitis in mice. The mouse model of mastitis was induced by injection of LPS through the duct of mammary gland. T0901317 was injected 1h before and 12h after induction of LPS intraperitoneally. The results showed that T0901317 significantly attenuated the infiltration of neutrophilic granulocytes, and the activation of myeloperoxidase (MPO); down-regulated the level of pro-inflammatory mediators including TNF-α, IL-1β, IL-6, COX-2 and PEG2; inhibited the phosphorylation of IκB-α and NF-κB p65, caused by LPS. Moreover, we report for the first time that LXR-α activation impaired LPS-induced mastitis. Taken together, these data indicated that T0901317 had protective effect on mastitis and the anti-inflammatory mechanism of T0901317 on LPS induced mastitis in mice may be due to its ability to inhibit NF-κB signaling pathway. LXR-α activation can be used as a therapeutic approach to treat mastitis. Copyright © 2014 Elsevier B.V. All rights reserved.

Tanshinone IIA Sodium Sulfonate Attenuates LPS-Induced Intestinal Injury in Mice

PubMed Central

Yang, Xin-Jing; Qian, Jin-Xian; Wei, Yao; Guo, Qiang; Jin, Jun; Sun, Xue; Liu, Sheng-Lan

2018-01-01

Background Tanshinone IIA sodium sulfonate (TSS) is known to possess anti-inflammatory effects and has exhibited protective effects in various inflammatory conditions; however, its role in lipopolysaccharide- (LPS-) induced intestinal injury is still unknown. Objective The present study is designed to explore the role and possible mechanism of TSS in LPS-induced intestinal injury. Methods Male C57BL/6J mice, challenged with intraperitoneal LPS injection, were treated with or without TSS 0.5 h prior to LPS exposure. At 1, 6, and 12 h after LPS injection, mice were sacrificed, and the small intestine was excised. The intestinal tissue injury was analyzed by HE staining. Inflammatory factors (TNF-α, IL-1β, and IL-6) in the intestinal tissue were examined by ELISA and RT-PCR. In addition, expressions of autophagy markers (microtubule-associated light chain 3 (LC3) and Beclin-1) were detected by western blot and RT-PCR. A number of autophagosomes were also observed under electron microscopy. Results TSS treatment significantly attenuated small intestinal epithelium injury induced by LPS. LPS-induced release of inflammatory mediators, including TNF-α, IL-1β, and IL-6, were markedly inhibited by TSS. Furthermore, TSS treatment could effectively upregulate LPS-induced decrease of autophagy levels, as evidenced by the increased expression of LC3 and Beclin-1, and more autophagosomes. Conclusion The protective effect of TSS on LPS-induced small intestinal injury may be attributed to the inhibition of inflammatory factors and promotion of autophagy levels. The present study may provide novel insight into the molecular mechanisms of TSS on the treatment of intestinal injury. PMID:29706995

Ursolic acid isolated from guava leaves inhibits inflammatory mediators and reactive oxygen species in LPS-stimulated macrophages.

PubMed

Kim, Min-Hye; Kim, Jin Nam; Han, Sung Nim; Kim, Hye-Kyeong

2015-06-01

Psidium guajava (guava) leaves have been frequently used for the treatment of rheumatism, fever, arthritis and other inflammatory conditions. The purpose of this study was to identify major anti-inflammatory compounds from guava leaf extract. The methanol extract and its hexane-, dichloromethane-, ethylacetate-, n-butanol- and water-soluble phases derived from guava leaves were evaluated to determine their inhibitory activity on nitric oxide (NO) production by RAW 264.7 cells stimulated with lipopolysaccharide (LPS). The methanol extract decreased NO production in a dose-dependent manner without cytotoxicity at a concentration range of 0-100 μg/mL. The n-butanol soluble phase was the most potent among the five soluble phases. Four compounds were isolated by reversed-phase HPLC from the n-butanol soluble phase and identified to be avicularin, guaijaverin, leucocyanidin and ursolic acid by their NMR spectra. Among these compounds, ursolic acid inhibited LPS-induced NO production in a dose-dependent manner without cytotoxity at a concentration range of 1-10 µM, but the other three compounds had no effect. Ursolic acid also inhibited LPS-induced prostaglandin E2 production. A western blot analysis showed that ursolic acid decreased the LPS-stimulated inducible nitric oxide synthase and cyclooxygenase protein levels. In addition, ursolic acid suppressed the production of intracellular reactive oxygen species in LPS-stimulated RAW 264.7 cells, as measured by flow cytometry. Taken together, these results identified ursolic acid as a major anti-inflammatory compound in guava leaves.

Quince (Cydonia oblonga Miller) peel polyphenols modulate LPS-induced inflammation in human THP-1-derived macrophages through NF-{kappa}B, p38MAPK and Akt inhibition

DOE Office of Scientific and Technical Information (OSTI.GOV)

Essafi-Benkhadir, Khadija; Refai, Amira; Riahi, Ichrak

Highlights: Black-Right-Pointing-Pointer Quince peel polyphenols inhibit LPS-induced secretion of TNF-{alpha} and IL-8. Black-Right-Pointing-Pointer Quince peel polyphenols augment LPS-induced secretion of IL-10 and IL-6. Black-Right-Pointing-Pointer Quince peel polyphenols-mediated inhibition of LPS-induced secretion of TNF-{alpha} is partially mediated by IL-6. Black-Right-Pointing-Pointer The anti-inflammatory effects of quince polyphenols pass through NF-{kappa}B, p38MAPK and Akt inhibition. -- Abstract: Chronic inflammation is a hallmark of several pathologies, such as rheumatoid arthritis, gastritis, inflammatory bowel disease, atherosclerosis and cancer. A wide range of anti-inflammatory chemicals have been used to treat such diseases while presenting high toxicity and numerous side effects. Here, we report the anti-inflammatory effectmore » of a non-toxic, cost-effective natural agent, polyphenolic extract from the Tunisian quince Cydonia oblonga Miller. Lipopolysaccharide (LPS) treatment of human THP-1-derived macrophages induced the secretion of high levels of the pro-inflammatory cytokine TNF-{alpha} and the chemokine IL-8, which was inhibited by quince peel polyphenolic extract in a dose-dependent manner. Concomitantly, quince polyphenols enhanced the level of the anti-inflammatory cytokine IL-10 secreted by LPS-treated macrophages. We further demonstrated that the unexpected increase in IL-6 secretion that occurred when quince polyphenols were associated with LPS treatment was partially responsible for the polyphenols-mediated inhibition of TNF-{alpha} secretion. Biochemical analysis showed that quince polyphenols extract inhibited the LPS-mediated activation of three major cellular pro-inflammatory effectors, nuclear factor-kappa B (NF-{kappa}B), p38MAPK and Akt. Overall, our data indicate that quince peel polyphenolic extract induces a potent anti-inflammatory effect that may prove useful for the treatment of inflammatory diseases and that a quince

Anti-inflammatory effects of novel polygonum multiflorum compound via inhibiting NF-κB/MAPK and upregulating the Nrf2 pathways in LPS-stimulated microglia.

PubMed

Park, Sun Young; Jin, Mei Ling; Kang, Nam Jun; Park, Geuntae; Choi, Young-Whan

2017-06-09

The incorporation of Polygonum multiflorum into the diet can result in anti-aging effects owing to its wide range of biological and pharmaceutical properties. We investigated the anti-neuroinflammatory properties of CRPE56IGIH isolated from P. multiflorum by focusing on its role in the induction of phase II antioxidant enzymes and the modulation of upstream signaling pathways. In microglia, CRPE56IGIH significantly inhibited lipopolysaccharide (LPS)-stimulated nitric oxide and prostaglandin E 2 production with nonspecific cytotoxicity. CRPE56IGIH also markedly inhibited LPS-inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 protein and mRNA expression in the same manner as it inhibited nitric oxide and prostaglandin E 2 production. In the control cells, NF-κB transactivation and nuclear translocation occurred at a baseline level, which was significantly increased in response to LPS. However, pretreatment with CRPE56IGIH concentration-dependently inhibited the LPS-induced NF-κB transactivation and nuclear translocation. The phosphorylation of Janus kinase-signal transducers and activators of transcription and mitogen-activated protein kinases was markedly upregulated by LPS, but considerably and dose-dependently inhibited by pretreatment with CRPE56IGIH. Furthermore, CRPE56IGIH induced the expression of phase II antioxidant enzymes, including heme oxygenase-1 (HO-1) and NADPH dehydrogenase quinone-1 (NQO-1). The activation of upstream signaling pathways, such as the Nrf2 pathway, was significantly increased following CRPE56IGIH treatment. Furthermore, the anti-neuroinflammatory effect of CRPE56IGIH was reversed by transfection of Nrf2, HO-1, and NQO-1 siRNA. Our results indicated that CRPE56IGIH isolated from P. multiflorum could be used as a natural anti-neuroinflammatory agent that induces phase II antioxidant enzymes via Nrf2 signaling. Copyright © 2017 Elsevier B.V. All rights reserved.

Doxycycline down-regulates matrix metalloproteinase expression and inhibits NF-κB signaling in LPS-induced PC3 cells.

PubMed

Ogut, Deniz; Reel, Buket; Gonen Korkmaz, Ceren; Arun, Mehmet Zuhuri; Cilaker Micili, Serap; Ergur, Bekir Ugur

2016-01-01

Matrix metalloproteinase enzymes (MMPs) play important role in inflammation, malignant cell proliferation, invasion and angiogenesis by mediating extracellular matrix degradation. Doxycycline, a synthetic tetracycline, behaves as a MMP inhibitor at a subantimicrobial dose and inhibits tumor cell proliferation, invasion and angiogenesis. The aberrant activity of nuclear factor kappa B (NF-κB) causes activation of MMPs and thereby proliferation and invasion of cancer cells. The aim of this study was to investigate the effects of doxycycline on the expression of MMPs in lipopolysaccharide (LPS)-induced PC3 human prostate cancer cells and the possible role of NF-κB signaling. PC3 cells were incubated with LPS (0.5 μg/mL) for 24 h in the presence or absence of doxycycline (5 μg/mL). The effects of LPS and doxycycline on the expressions of MMP-2, MMP-8, MMP-9, MMP-10, NF-κB/p65, IκB-α, p-IκB-α, IKK-β were examined by Western blotting and immunohistochemistry in PC3 cells. Furthermore, relative proteinase activities of MMP-2 and MMP-9 were determined by gelatin zymography. LPS increased expression and activity of MMP-9 and expression of MMP-8, MMP-10, NF-κB /p65, p-IκB-α, IKK-β and doxycycline down-regulated its effects with the exception of MMP-10 expression. The expression of MMP-2 and IκB-α was affected by neither LPS nor doxycycline. Our findings indicate that doxycycline inhibits the expression of various MMPs and NF-κB signaling may play a role in the regulation of MMPs expression in LPS-induced PC3 human prostate cancer cells.

A butyrolactone derivative suppressed lipopolysaccharide-induced autophagic injury through inhibiting the autoregulatory loop of p8 and p53 in vascular endothelial cells.

PubMed

Meng, Ning; Zhao, Jing; Su, Le; Zhao, Baoxiang; Zhang, Yun; Zhang, Shangli; Miao, Junying

2012-02-01

Lipopolysaccharide (LPS)-induced vascular endothelial cell (VEC) dysfunction is an important contributing factor in vascular diseases. Recently, we found that LPS impaired VEC by inducing autophagy. Our previous researches showed that a butyrolactone derivative, 3-benzyl-5-((2-nitrophenoxy) methyl)-dihydrofuran-2(3H)-one (3BDO) selectively protected VEC function. The objective of the present study is to investigate whether and how 3BDO inhibits LPS-induced VEC autophagic injury. Our results showed that LPS induced autophagy and led to increase of reactive oxygen species (ROS) and decrease of mitochondrial membrane potential (MMP) in Human umbilical vein vascular endothelial cells (HUVECs). Furthermore, LPS significantly increased p8 and p53 protein levels and the nuclear translocation of p53. All of these effects of LPS on HUVECs were strongly inhibited by 3BDO. Importantly, the ROS scavenger N-acetylcysteine (NAC) could inhibited LPS-induced autophagy and knockdown of p8 by RNA interference inhibited the autophagy, p53 protein level increase, the translocation of p53 into nuclei and the ROS level increase induced by LPS in HUVECs. The data suggested that 3BDO inhibited LPS-induced autophagy in HUVECs through inhibiting the ROS overproduction, the increase of p8 and p53 expression and the nuclear translocation of p53. Our findings provide a potential tool for understanding the mechanism underlying LPS-induced autophagy in HUVECs and open the door to a novel therapeutic drug for LPS-induced vascular diseases. Copyright © 2011 Elsevier Ltd. All rights reserved.

NZ suppresses TLR4/NF-κB signalings and NLRP3 inflammasome activation in LPS-induced RAW264.7 macrophages.

PubMed

Xiang, Pengjun; Chen, Tong; Mou, Yi; Wu, Hui; Xie, Peng; Lu, Guo; Gong, Xiaojian; Hu, Qinghua; Zhang, Yihua; Ji, Hui

2015-10-01

The purpose of the present study was to evaluate the potential therapeutic effects of NZ on lipopolysaccharide (LPS)-induced RAW264.7 cells and explore its underlying mechanisms. The effect of NZ on NO generation in LPS-activated macrophage was measured by Griess assay. The concentrations of TNF-α, IL-18, IL-1β were analyzed with ELISA kits. The LPS-induced production of reactive oxygen species (ROS) was determined by flow cytometry. The protein expressions of TLR4, NF-κB and NLRP3 signaling pathway were investigated with Western blot analysis. It was shown that NZ significantly reduced the production of NO and the generation of pro-inflammatory cytokines in LPS-induced RAW264.7 cells. In addition, NZ markedly inhibited the up-regulation of toll-like receptor 4 (TLR4), myeloid differentiation factor 88 (MyD88) and the activation of nuclear factor kappa B (NF-κB) in LPS-stimulated RAW 264.7 macrophages. Of note, NZ suppressed the expression of the inflammasome component such as NOD-like receptor 3(NLRP3), apoptosis-associated speck-like protein containing CARD(ASC), as well as the levels of cytokines including Interleukin-18(IL-18) and Interleukin-1β(IL-1β). These results indicated that NZ inhibited the generations of NO and pro-inflammatory cytokines by suppressing TLR4/MyD88/NF-κB pathway, suggesting that NZ could be an effective candidate for ameliorating LPS-induced inflammatory responses.

Resveratrol inhibits LPS-induced mice mastitis through attenuating the MAPK and NF-κB signaling pathway.

PubMed

Zhang, Xu; Wang, Yanan; Xiao, Chong; Wei, Zhengkai; Wang, Jingjing; Yang, Zhengtao; Fu, Yunhe

2017-06-01

Resveratrol is a natural polyphenol extracted from mangy plants. It has been reported that resveratrol show multitudinous positive role in biology such as anti-oxidant, anti-nociception and anti-inflammatory effects. Therefore, the present study devotes to test the effect of resveratrol on LPS-induced mastitis in mice. Resveratrol was administered intraperitoneally 1 h before LPS treatment. And the anti-inflammatory effect of resveratrol was measured by histopathological examination, MPO assay, real-time PCR and western blotting analysis. The results showed that resveratrol significantly reduced the LPS-induced mammary histopathological changes. Meanwhile, it sharply attenuated the activity of MPO. The result also indicated that the resveratrol can decrease the expression of pro-inflammatory cytokines TNF-α and IL-1β. From the results of western blotting, resveratrol suppressed the expression of phosphorylation of p65 and IκB from NF-κB signal pathway and phosphorylation of p38 and ERK from MAPK signal pathway. These findings suggested that resveratrol may inhibit the inflammatory response in the mastitis. Copyright © 2017 Elsevier Ltd. All rights reserved.

Thalidomide inhibits lipopolysaccharide-induced tumor necrosis factor-alpha production via down-regulation of MyD88 expression.

PubMed

Noman, Abu Shadat M; Koide, Naoki; Hassan, Ferdaus; I-E-Khuda, Imtiaz; Dagvadorj, Jargalsaikhan; Tumurkhuu, Gantsetseg; Islam, Shamima; Naiki, Yoshikazu; Yoshida, Tomoaki; Yokochi, Takashi

2009-02-01

The effect of thalidomide on lipopolysaccharide (LPS)-induced tumor necrosis factor (TNF)-alpha production was studied by using RAW 264.7 murine macrophage-like cells. Thalidomide significantly inhibited LPS-induced TNF-alpha production. Thalidomide prevented the activation of nuclear factor (NF)-KB by down-regulating phosphorylation of inhibitory KB factor (IKB), and IKB kinase (IKK)-alpha and IKK-beta Moreover, thalidomide inhibited LPS-induced phosphorylation of AKT, p38 and stress-activated protein kinase (SAPK)/JNK. The expression of myeloid differentiation factor 88 (MyD88) protein and mRNA was markedly reduced in thalidomide-treated RAW 264.7 cells but there was no significant alteration in the expression of interleukin-1 receptor-associated kinase (IRAK) 1 and TNF receptor-associated factor (TRAF) 6 in the cells. Thalidomide did not affect the cell surface expression of Toll-like receptor (TLR) 4 and CD14, suggesting the impairment of intracellular LPS signalling in thalidomide-treated RAW 264.7 cells. Thalidomide significantly inhibited the TNF-alpha production in response to palmitoyl-Cys(RS)-2,3-di(palmitoyloxy) propyl)-Ala-Gly-OH (Pam(3)Cys) as a MyD88-dependent TLR2 ligand. Therefore, it is suggested that thalidomide might impair LPS signalling via down-regulation of MyD88 protein and mRNA and inhibit LPS-induced TNF-alpha production. The putative mechanism of thalidomide-induced MyD88 down-regulation is discussed.

Ilexgenin A, a novel pentacyclic triterpenoid extracted from Aquifoliaceae shows reduction of LPS-induced peritonitis in mice.

PubMed

Sun, Weidong; Liu, Chang; Zhang, Yaqi; Qiu, Xia; Zhang, Li; Zhao, Hongxia; Rong, Yi; Sun, Yun

2017-02-15

Ilexgenin A (IA) is a novel pentacyclic triterpenoid, which extracted from leaves of Ilex hainanensis Merr. In the present study, we aim to explore anti-inflammatory activity of IA on LPS-induced peritonitis and its underlying molecular mechanism. The results determined that IA was capable of suppressing peritonitis in mice induced by intraperitoneal (i.p.) injection of lipopolysaccaride (LPS). Furthermore, the results showed that IA dramatically inhibited levels of inflammatory cells infiltration in peritoneal cavity and serum in LPS-induced mice peritonitis model. Besides, IA could dramatically inhibit levels of inflammatory cytokines (IL-1β, IL-6 and TNF-α) in peritoneal cavity in LPS-induced mice peritonitis model. In vitro study, the results showed that IA inhibited production of IL-1β, IL-6 and TNF-α at transcriptional and translational levels in RAW 264.7 cells induced by LPS. Furthermore, IA could suppress the LPS-induced activation of Akt and downstream degradation and phosphorylation of kappa B-α (IκB-α). Moreover, IA could significantly inhibit ERK 1/2 phosphorylation in RAW 264.7 cells induced by LPS. These results were concurrent with molecular docking which revealed ERK1/2 inhibition. These results demonstrated that IA might as an anti-inflammatory agent candidate for inflammatory disease therapy. Copyright © 2017 Elsevier B.V. All rights reserved.

Boehmeria nivea attenuates LPS-induced inflammatory markers by inhibiting p38 and JNK phosphorylations in RAW264.7 macrophages.

PubMed

Sung, Mi Jeong; Davaatseren, Munkhtugs; Kim, Sung Hee; Kim, Min Jung; Hwang, Jin-Taek

2013-09-01

Boehmeria nivea (Linn.) Gaudich (Urticaceae), a natural herb, has a long history of treating several diseases including wound healing. However, the anti-inflammatory effect of B. nivea has not been investigated. We investigated whether the 70% ethanol extract of B. nivea (Ebn) can exert anti-inflammatory activity. Several phenolic compounds of extracts were determined to provide further information on the correlation between anti-inflammatory effects and phenolic compounds. We prepared a 70% ethanol extract of B. nivea leaves and evaluated its anti-inflammatory activity (200, 400, 800, 1200 µg/mL) by measuring the secretions of nitric oxide (NO), tumor necrosis factor alpha (TNF-α) and interleukin 6 (IL-6), which were stimulated by lipopolysaccharide (LPS) in RAW264.7 macrophages. The total phenolic compounds were determined by the Folin-Ciocalteu method and major compounds were determined by HPLC. Ebn was able to abolish the LPS-induced secretions of NO, TNF-α and IL-6. It also decreased the protein levels (IC₅₀ = 186 µg/mL) of LPS-induced inducible nitric oxide synthase (iNOS). The LPS stimulated p38, JNK and ERK phosphorylations significantly more than the controls. Surprisingly, although Ebn reduced p38 and JNK phosphorylations, it did not influence ERK phosphorylation. We found that Ebn revealed several major compounds such as chlorogenic acid (1.96 mg/100 g), rutin (46.48 mg/100 g), luteolin-7-glucoside (11.29 mg/100 g), naringin (1.13 mg/100 g), hesperidin (23.69 mg/100 g) and tangeretin (1.59 mg/100 g). Boehmeria nivea exerts an anti-inflammatory effect on macrophages by inhibiting p38 and JNK, suggesting that it may be used as a functional ingredient against inflammation.

Anti-inflammatory effect of garlic 14-kDa protein on LPS-stimulated-J774A.1 macrophages.

PubMed

Rabe, Shahrzad Zamani Taghizadeh; Ghazanfari, Tooba; Siadat, Zahra; Rastin, Maryam; Rabe, Shahin Zamani Taghizadeh; Mahmoudi, Mahmoud

2015-04-01

Garlic 14-kDa protein is purified from garlic (Allium sativum L.) which is used in traditional medicine and exerts various immunomodulatory activities. The present study investigated the suppressive effect of garlic 14-kDa protein on LPS-induced expression of pro-inflammatory mediators and underlying mechanism in inflammatory macrophages. J774A.1 macrophages were treated with 14-kDa protein (5-30 μg/ml) with/without LPS (1 μg/ml) and the production of inflammatory mediators such as prostaglandin E2 (PGE2), TNF-α, and IL-1β released were measured using ELISA. Nitric oxide (NO) production was determined using the Griess method. The anti-inflammatory activity of 14-kDa protein was examined by measuring inducible nitric oxide synthase and cyclooxygenase-2 proteins using western blot. The expression of nuclear NF-κB p65 subunit was assessed by western blot. Garlic 14-kDa protein significantly inhibited the excessive production of NO, PGE, TNF-α, and IL-1β in lipopolysaccharide (LPS)-activated J774A.1 macrophages in a concentration-related manner without cytotoxic effect. Western blot analysis demonstrated that garlic 14-kDa protein suppressed corresponding inducible NO synthase expression and activated cyclooxygenase-2 protein expression. The inhibitory effect was mediated partly by a reduction in the activity and expression of transcription factor NF-κB protein. Our results suggested, for the first time, garlic 14-kDa protein exhibits anti-inflammatory properties in macrophages possibly by suppressing the inflammatory mediators via the inhibition of transcription factor NF-κB signaling pathway. The traditional use of garlic as anti-inflammatory remedy could be ascribed partly to 14-kDa protein content. This protein might be a useful candidate for controlling inflammatory diseases and further investigations in vivo.

Involvement of JNK and NF-κB pathways in lipopolysaccharide (LPS)-induced BAG3 expression in human monocytic cells.

PubMed

Wang, Hua-Qin; Meng, Xin; Liu, Bao-Qin; Li, Chao; Gao, Yan-Yan; Niu, Xiao-Fang; Li, Ning; Guan, Yifu; Du, Zhen-Xian

2012-01-01

Lipopolysaccharide (LPS) is an outer-membrane glycolipid component of Gram-negative bacteria known for its fervent ability to activate monocytic cells and for its potent proinflammatory capabilities. Bcl-2-associated athanogene 3 (BAG3) is a survival protein that has been shown to be stimulated during cell response to stressful conditions, such as exposure to high temperature, heavy metals, proteasome inhibition, and human immunodeficiency virus 1 (HIV-1) infection. In addition, BAG3 regulates replication of Varicella-Zoster Virus (VZV) and Herpes Simplex Virus (HSV) replication, suggesting that BAG3 could participate in the host response to infection. In the current study, we found that LPS increased the expression of BAG3 in a dose- and time-dependent manner. Actinomycin D completely blocked the LPS-induced BAG3 accumulation, as well as LPS activated the proximal promoter of BAG3 gene, supported that the induction by LPS occurred at the level of gene transcription. LPS-induced BAG3 expression was blocked by JNK or NF-κB inhibition, suggesting that JNK and NF-κB pathways participated in BAG3 induction by LPS. In addition, we also found that induction of BAG3 was implicated in monocytic cell adhesion to extracellular matrix induced by LPS. Overall, the data support that BAG3 is induced by LPS via JNK and NF-κB-dependent signals, and involved in monocytic cell-extracellular matrix interaction, suggesting that BAG3 may have a role in the host response to LPS stimulation. Copyright © 2011 Elsevier Inc. All rights reserved.

Effect of azithromycin on the LPS-induced production and secretion of phospholipase A2 in lung cells.

PubMed

Kitsiouli, Eirini; Antoniou, Georgia; Gotzou, Helen; Karagiannopoulos, Michalis; Basagiannis, Dimitris; Christoforidis, Savvas; Nakos, George; Lekka, Marilena E

2015-07-01

Azithromycin is a member of macrolides, utilized in the treatment of infections. Independently, these antibiotics also possess anti-inflammatory and immunomodulatory properties. Phospholipase A2 isotypes, which are implicated in the pathophysiology of inflammatory lung disorders, are produced by alveolar macrophages and other lung cells during inflammatory response and can promote lung injury by destructing lung surfactant. The aim of the study was to investigate whether in lung cells azithromycin can inhibit secretory and cytosolic phospholipases A2, (sPLA2) and (cPLA2), respectively, which are induced by an inflammatory trigger. In this respect, we studied the lipopolysaccharide (LPS)-mediated production or secretion of sPLA2 and cPLA2 from A549 cells, a cancer bronchial epithelial cell line, and alveolar macrophages, isolated from bronchoalveolar lavage fluid of ARDS and control patients without cardiopulmonary disease or sepsis. Pre-treatment of cells with azithromycin caused a dose-dependent decrease in the LPS-induced sPLA2-IIA levels in A549 cells. This inhibition was rather due to reduced PLA2G2A mRNA expression and secretion of sPLA2-IIA protein levels, as observed by western blotting and indirect immunofluorescence by confocal microscopy, respectively, than to the inhibition of the enzymic activity per se. On the contrary, azithromycin had no effect on the LPS-induced production or secretion of sPLA2-IIA from alveolar macrophages. The levels of LPS-induced c-PLA2 were not significantly affected by azithromycin in either cell type. We conclude that azithromycin exerts anti-inflammatory properties on lung epithelial cells through the inhibition of both the expression and secretion of LPS-induced sPLA2-IIA, while it does not affect alveolar macrophages. Copyright © 2015 Elsevier B.V. All rights reserved.

Bee Venom Decreases LPS-Induced Inflammatory Responses in Bovine Mammary Epithelial Cells.

PubMed

Jeong, Chang Hee; Cheng, Wei Nee; Bae, Hyojin; Lee, Kyung Woo; Han, Sang Mi; Petriello, Michael C; Lee, Hong Gu; Seo, Han Geuk; Han, Sung Gu

2017-10-28

The world dairy industry has long been challenged by bovine mastitis, an inflammatory disease, which causes economic loss due to decreased milk production and quality. Attempts have been made to prevent or treat this disease with multiple approaches, primarily through increased abuse of antibiotics, but effective natural solutions remain elusive. Bee venom (BV) contains a variety of peptides ( e.g. , melittin) and shows multiple bioactivities, including prevention of inflammation. Thus, in the current study, it was hypothesized that BV can reduce inflammation in bovine mammary epithelial cells (MAC-T). To examine the hypothesis, cells were treated with LPS (1 μg/ml) to induce an inflammatory response and the anti-inflammatory effects of BV (2.5 and 5 μg/ml) were investigated. The cellular mechanisms of BV against LPS-induced inflammation were also investigated. Results showed that BV can attenuate expression of an inflammatory protein, COX2, and pro-inflammatory cytokines such as IL-6 and TNF-α. Activation of NF-κB, an inflammatory transcription factor, was significantly downregulated by BV in cells treated with LPS, through dephosphorylation of ERK1/2. Moreover, pretreatment of cells with BV attenuated LPS-induced production of intracellular reactive oxygen species ( e.g. , superoxide anion). These results support our hypothesis that BV can decrease LPS-induced inflammatory responses in bovine mammary epithelial cells through inhibition of oxidative stress, NF-κB, ERK1/2, and COX-2 signaling.

Apomorphine prevents LPS-induced IL-23 p19 mRNA expression via inhibition of JNK and ATF4 in HAPI cells.

PubMed

Hara, Hirokazu; Kimoto, Dai; Kajita, Miho; Takada, Chisato; Kamiya, Tetsuro; Adachi, Tetsuo

2017-01-15

Inflammation has been reported to be closely related to exaggeration of cerebral ischemia and neurodegenerative diseases. Microglia, resident immune cells in the central nervous system, can be activated in response to neuronal injury and produce proinflammatory cytokines, resulting in further aggravation of neuronal injury. Interleukin (IL)-23, which consists of p19 and IL-12 p40 subunits, has been shown to be involved in brain injury associated with neuroinflammation. Apomorphine (Apo), a nonselective dopamine receptor agonist, has been used for clinical therapy of Parkinson's disease. Besides the pharmacological effect, Apo is known to have pleiotropic biological functions. In this study, to elucidate the effect of Apo on lipopolysaccharide (LPS)-induced IL-23 p19 mRNA expression in microglial cell line HAPI cells, we pretreated cells with various concentrations of Apo (10 - 30μM) for 8, 16, and 24h, followed by exposure to LPS (100ng/ml). Pretreatment with Apo dose- and time-dependently suppressed the induction of IL-23 p19 mRNA. However, this effect of Apo was exerted independently of dopamine receptors. JNK and ATF4, an endoplasmic reticulum (ER) stress-inducible transcription factor, were involved in expression of LPS-induced IL-23 p19 mRNA. Pretreatment with Apo (30μM) for 24h inhibited LPS-induced activation of JNK and the nuclear accumulation of ATF4. Thapsigargin (Tg), an ER stress inducer, stimulated IL-23 p19 mRNA expression via an ATF4 dependent mechanism. We also found that Apo inhibited Tg-induced ATF4 accumulation and IL-23 p19 mRNA expression. Taken together, our findings suggest that Apo exerts anti-inflammatory effects through inhibition of JNK and ATF4 signaling pathways. Copyright © 2016 Elsevier B.V. All rights reserved.

Oxymatrine lightened the inflammatory response of LPS-induced mastitis in mice through affecting NF-κB and MAPKs signaling pathways.

PubMed

Yang, Zhengtao; Yin, Ronglan; Cong, Yunfeng; Yang, Zhanqing; Zhou, Ershun; Wei, Zhengkai; Liu, Zhicheng; Cao, Yongguo; Zhang, Naisheng

2014-12-01

Mastitis, an inflammatory reaction of the mammary gland, is recognized as one of the most costly diseases in dairy cattle. Oxymatrine, one of the alkaloids extracted from Chinese herb Sophora flavescens Ait, has been reported to have many biological activities, such as anti-inflammatory, anti-virus, and anti-hepatic fibrosis properties. The aim of this study was to investigate the protective effect and the anti-inflammatory mechanism of oxymatrine on lipopolysaccharide (LPS)-induced mastitis in mice. The mouse mastitis was induced by 10 μg of LPS for 24 h. Oxymatrine was intraperitoneally administered with the dose of 30, 60, and 120 mg/kg 1 h before and 12 h after LPS induction. The results showed that oxymatrine significantly attenuated the damage of the mammary gland induced by LPS. Oxymatrine inhibited the phosphorylation of NF-κB p65 and IκB in NF-κB signal pathway and reduced the phosphorylation of p38, ERK, and JNK in mitogen-activated protein kinase (MAPKs) signal pathway. The results showed that oxymatrine had a protective effect on LPS-induced mastitis, and the anti-inflammatory mechanism of oxymatrine was related to the inhibition of NF-κB and MAPKs signal pathways.

Pepsin-pancreatin protein hydrolysates from extruded amaranth inhibit markers of atherosclerosis in LPS-induced THP-1 macrophages-like human cells by reducing expression of proteins in LOX-1 signaling pathway

PubMed Central

2014-01-01

Background Atherosclerosis is considered a progressive disease that affects arteries that bring blood to the heart, to the brain and to the lower end. It derives from endothelial dysfunction and inflammation, which play an important role in the thrombotic complications of atherosclerosis. Cardiovascular disease is the leading cause of death around the world and one factor that can contribute to its progression and prevention is diet. Our previous study found that amaranth hydrolysates inhibited LPS-induced inflammation in human and mouse macrophages by preventing activation of NF-κB signaling. Furthermore, extrusion improved the anti-inflammatory effect of amaranth protein hydrolysates in both cell lines, probably attributed to the production of bioactive peptides during processing. Therefore, the objective of this study was to compare the anti-atherosclerotic potential of pepsin-pancreatin hydrolysates from unprocessed and extruded amaranth in THP-1 lipopolysaccharide-induced human macrophages and suggest the mechanism of action. Results Unprocessed amaranth hydrolysate (UAH) and extruded amaranth hydrolysate (EAH) showed a significant reduction in the expression of interleukin-4 (IL-4) (69% and 100%, respectively), interleukin-6 (IL-6) (64% and 52%, respectively), interleukin-22 (IL-22) (55% and 70%, respectively). Likewise, UAH and EAH showed a reduction in the expression of monocyte-chemo attractant protein-1 (MCP-1) (35% and 42%, respectively), transferrin receptor-1 (TfR-1) (48% and 61%, respectively), granulocyte-macrophage colony-stimulating factor (GM-CSF) (59% and 63%, respectively), and tumor necrosis factor-α (TNF-α) (60% and 63%, respectively). Also, EAH reduced the expression of lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) (27%), intracellular adhesion molecule-1 (ICAM-1) (28%) and matrix metalloproteinase-9 (MMP-9) (19%), important molecular markers in the atherosclerosis pathway. EAH, led to a reduction of 58, 52 and 79% for

Anti-Inflammatory Effect of Apigenin on LPS-Induced Pro-Inflammatory Mediators and AP-1 Factors in Human Lung Epithelial Cells.

PubMed

Patil, Rajeshwari H; Babu, R L; Naveen Kumar, M; Kiran Kumar, K M; Hegde, Shubha M; Nagesh, Rashmi; Ramesh, Govindarajan T; Sharma, S Chidananda

2016-02-01

Apigenin is one of the plant flavonoids present in fruits and vegetables, acting as an important nutraceutical component. It is recognized as a potential antioxidant, antimicrobial, and anti-inflammatory molecule. In the present study, the mechanism of anti-inflammatory action of apigenin on lipopolysaccharide (LPS)-induced pro-inflammatory cytokines and activator protein-1 (AP-1) factors in human lung A549 cells was investigated. The anti-inflammatory activity of apigenin on LPS-induced inflammation was determined by analyzing the expression of pro-inflammatory cytokines, nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), and different AP-1 factors. Apigenin significantly inhibited the LPS-induced expression of iNOS, COX-2, expression of pro-inflammatory cytokines (IL-1β, IL-2, IL-6, IL-8, and TNF-α), and AP-1 proteins (c-Jun, c-Fos, and JunB) including nitric oxide production. Study confirms the anti-inflammatory effect of apigenin by inhibiting the expression of inflammatory mediators and AP-1 factors involved in the inflammation and its importance in the treatment of lung inflammatory diseases.

Wogonin but not Nor-wogonin inhibits lipopolysaccharide and lipoteichoic acid-induced iNOS gene expression and NO production in macrophages.

PubMed

Huang, Guan-Cheng; Chow, Jyh-Ming; Shen, Shing-Chuan; Yang, Liang-Yo; Lin, Cheng-Wei; Chen, Yen-Chou

2007-08-01

Wogonin (Wog; 5,7-dihydroxy-8-methoxy flavone) has been shown to effectively inhibit lipopolysaccharide (LPS)-induced inducible nitric oxide synthase (iNOS) gene expression and nitric oxide production in our previous study. In the present study, we found that Nor-wogonin (N-Wog; 5,7,8-trihydroxyl flavone), a structural analogue of Wog with an OH substitution at C8, performed different effect on LPS- or lipoteichoic acid (LTA)-induced iNOS gene expression and nitric oxide (NO) production in macrophages. Wog, but not N-Wog, significantly inhibits LPS- or LTA-induced NO production through suppressing iNOS gene expression at both protein and mRNA without affecting NO donor sodium nitroprusside-induced NO production, NOS enzyme activity, and cells viability. Activation of JNKs (not ERKs) via phosphorylation induction, and an increase in c-Jun (not c-Fos) protein expression were involved in LPS- and LTA-treated RAW264.7 cells, and those events were blocked by Wog, but not N-Wog, addition. Furthermore, 5,7-diOH flavone, but not 5-OH flavone, 7-OH flavone, 5-OH-7-OCH(3) flavone, significantly inhibits LPS-induced iNOS protein expression and NO production, and 7,8-diOCH(3) flavone performs more effective inhibitory activity on LPS-induced NO production and iNOS protein expression than 7-OCH(3)-8-OH flavone. These data suggest that OHs at both C5 and C7 are essential for NO inhibition of flavonoids, and OCH(3) at C8 may contribute to this activity, and suppression of JNKs-c-Jun activation is involved.

Intranuclear interactomic inhibition of NF-κB suppresses LPS-induced severe sepsis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Park, Sung-Dong; Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, Seoul 120-749; Cheon, So Yeong

Suppression of nuclear factor-κB (NF-κB) activation, which is best known as a major regulator of innate and adaptive immune responses, is a potent strategy for the treatment of endotoxic sepsis. To inhibit NF-κB functions, we designed the intra-nuclear transducible form of transcription modulation domain (TMD) of RelA (p65), called nt-p65-TMD, which can be delivered effectively into the nucleus without influencing the cell viability, and work as interactomic inhibitors via disruption of the endogenous p65-mediated transcription complex. nt-p65-TMD effectively inhibited the secretion of pro-inflammatory cytokines, including TNF-α, IL-1β, or IL-6 from BV2 microglia cells stimulated by lipopolysaccharide (LPS). nt-p65-TMD did notmore » inhibit tyrosine phosphorylation of signaling mediators such as ZAP-70, p38, JNK, or ERK involved in T cell activation, but was capable of suppressing the transcriptional activity of NF-κB without the functional effect on that of NFAT upon T-cell receptor (TCR) stimulation. The transduced nt-p65-TMD in T cell did not affect the expression of CD69, however significantly inhibited the secretion of T cell-specific cytokines such as IL-2, IFN-γ, IL-4, IL-17A, or IL-10. Systemic administration of nt-p65-TMD showed a significant therapeutic effect on LPS-induced sepsis model by inhibiting pro-inflammatory cytokines secretion. Therefore, nt-p65-TMD can be a novel therapeutics for the treatment of various inflammatory diseases, including sepsis, where a transcription factor has a key role in pathogenesis, and further allows us to discover new functions of p65 under normal physiological condition without genetic alteration. - Highlights: • The nt-p65-TMD is intra-nuclear interactomic inhibitor of endogenous p65. • The nt-p65-TMD effectively inhibited the secretion of pro-inflammatory cytokines. • The excellent therapeutic potential of nt-p65-TMD was confirmed in sepsis model.« less

Crocin Suppresses LPS-Stimulated Expression of Inducible Nitric Oxide Synthase by Upregulation of Heme Oxygenase-1 via Calcium/Calmodulin-Dependent Protein Kinase 4

PubMed Central

Kim, Ji-Hee; Park, Ga-Young; Bang, Soo Young; Park, Sun Young; Bae, Soo-Kyung; Kim, YoungHee

2014-01-01

Crocin is a water-soluble carotenoid pigment that is primarily used in various cuisines as a seasoning and coloring agent, as well as in traditional medicines for the treatment of edema, fever, and hepatic disorder. In this study, we demonstrated that crocin markedly induces the expression of heme oxygenase-1 (HO-1) which leads to an anti-inflammatory response. Crocin inhibited inducible nitric oxide synthase (iNOS) expression and nitric oxide production via downregulation of nuclear factor kappa B activity in lipopolysaccharide- (LPS-) stimulated RAW 264.7 macrophages. These effects were abrogated by blocking of HO-1 expression or activity. Crocin also induced Ca2+ mobilization from intracellular pools and phosphorylation of Ca2+/calmodulin-dependent protein kinase 4 (CAMK4). CAMK4 knockdown and kinase-dead mutant inhibited crocin-mediated HO-1 expression, Nrf2 activation, and phosphorylation of Akt, indicating that HO-1 expression is mediated by CAMK4 and that Akt is a downstream mediator of CAMK4 in crocin signaling. Moreover, crocin-mediated suppression of iNOS expression was blocked by CAMK4 inhibition. Overall, these results suggest that crocin suppresses LPS-stimulated expression of iNOS by inducing HO-1 expression via Ca2+/calmodulin-CAMK4-PI3K/Akt-Nrf2 signaling cascades. Our findings provide a novel molecular mechanism for the inhibitory effects of crocin against endotoxin-mediated inflammation. PMID:24839356

Indoline-3-propionate and 3-aminopropyl carbamates reduce lung injury and pro-inflammatory cytokines induced in mice by LPS.

PubMed

Finkin-Groner, E; Moradov, D; Shifrin, H; Bejar, C; Nudelman, A; Weinstock, M

2015-02-01

In the search for safer and effective anti-inflammatory agents, we investigated the effect of methyl indoline-3-propionate and indoline-3-(3-aminopropyl) carbamates on LPS-induced lung injury and pro-inflammatory cytokines in mice. Their mechanism of action was determined in murine peritoneal macrophages. Lung injury was induced by intratracheal infusion of LPS and assessed by the change in lung weight and structure by light microscopy after staining by haematoxylin and eosin. In LPS-activated macrophages, MAPK proteins and IκBα were measured by Western blotting and the transcription factors, AP-1 and NF-κB by electromobility shift assay. Cytokines in the plasma and spleen of mice injected with LPS were measured by elisa-based assay. AN917 and AN680 (1-10 pM) decreased TNF-α protein in macrophages by inhibiting phosphorylation of p38 MAPK, IκBα degradation and activation of AP-1 and NF-κB without affecting cell viability. In vivo, these compounds (10 μmol · kg(-1)) markedly decreased lung injury induced by LPS and the elevation of TNF-α and IL-6 in lung, plasma and spleen. Activation of α-7nACh receptors contributed to the reduction of TNF-α by AN917, which inhibited AChE in the spleen by 35%. Indoline carbamates are potent inhibitors of pro-inflammatory mediators in murine macrophages and in mice injected with LPS, acting via the p38 MAPK, AP-1 and NF-κB cascades. Indirect α-7nACh receptor activation by AN917, through inhibition of AChE, contributes to its anti-inflammatory effect. Indoline carbamates may have therapeutic potential for lung injury and other diseases associated with chronic inflammation without causing immunosuppression. © 2014 The British Pharmacological Society.

Indoline-3-propionate and 3-aminopropyl carbamates reduce lung injury and pro-inflammatory cytokines induced in mice by LPS

PubMed Central

Finkin-Groner, E; Moradov, D; Shifrin, H; Bejar, C; Nudelman, A; Weinstock, M

2015-01-01

Background and Purpose In the search for safer and effective anti-inflammatory agents, we investigated the effect of methyl indoline-3-propionate and indoline-3-(3-aminopropyl) carbamates on LPS-induced lung injury and pro-inflammatory cytokines in mice. Their mechanism of action was determined in murine peritoneal macrophages. Experimental Approach Lung injury was induced by intratracheal infusion of LPS and assessed by the change in lung weight and structure by light microscopy after staining by haematoxylin and eosin. In LPS-activated macrophages, MAPK proteins and IκBα were measured by Western blotting and the transcription factors, AP-1 and NF-κB by electromobility shift assay. Cytokines in the plasma and spleen of mice injected with LPS were measured by elisa-based assay. Key Results AN917 and AN680 (1–10 pM) decreased TNF-α protein in macrophages by inhibiting phosphorylation of p38 MAPK, IκBα degradation and activation of AP-1 and NF-κB without affecting cell viability. In vivo, these compounds (10 μmol·kg−1) markedly decreased lung injury induced by LPS and the elevation of TNF-α and IL-6 in lung, plasma and spleen. Activation of α-7nACh receptors contributed to the reduction of TNF-α by AN917, which inhibited AChE in the spleen by 35%. Conclusion and Implications Indoline carbamates are potent inhibitors of pro-inflammatory mediators in murine macrophages and in mice injected with LPS, acting via the p38 MAPK, AP-1 and NF-κB cascades. Indirect α-7nACh receptor activation by AN917, through inhibition of AChE, contributes to its anti-inflammatory effect. Indoline carbamates may have therapeutic potential for lung injury and other diseases associated with chronic inflammation without causing immunosuppression. PMID:25322956

RETRACTED: Sophocarpine displays anti-inflammatory effect via inhibiting TLR4 and TLR4 downstream pathways on LPS-induced mastitis in the mammary gland of mice.

PubMed

Wang, Dehai; Xu, Niannian; Zhang, Zhenbiao; Yang, Shijin; Qiu, Changwei; Li, Chengye; Deng, Ganzhen; Guo, Mengyao

2016-06-01

Mastitis is defined as the inflammation of the mammary gland. LPS, which is widely used to induce mastitis models for the study of this disease, triggers similar inflammation as Escherichia coli. Sophocarpine, isolated from Sophora alopecuroides L., exhibits multiple biological properties. The aim of the present study was to determine the anti-inflammatory effect and mechanism of action of sophocarpine on mastitis within an LPS-induced mouse model. ELISA and western blotting were performed to detect protein levels. The qPCR was performed to detect mRNA levels. The ELISA and qRT-PCR results showed that sophocarpine inhibited the expression of TNF-α, IL-1β and IL-6 in a dose-dependent manner. However, sophocarpine suppressed TLR4 expression. Further study showed that sophocarpine could suppress the phosphorylation of IκBα, p65 and p38. These results confirm that sophocarpine played an anti-inflammatory role in LPS-induced mastitis by regulating TLR4 and the NF-κB and MAPK signaling pathways in mammary gland tissues. Therefore, sophocarpine may be a potential therapeutic drug for the treatment of mastitis. Copyright © 2016 Elsevier B.V. All rights reserved.

The binding capability of plasma phospholipid transfer protein, but not HDL pool size, is critical to repress LPS induced inflammation.

PubMed

Yu, Yang; Cui, Yingjie; Zhao, Yanan; Liu, Shuai; Song, Guohua; Jiao, Peng; Li, Bin; Luo, Tian; Guo, Shoudong; Zhang, Xiangjian; Wang, Hao; Jiang, Xian-Cheng; Qin, Shucun

2016-02-09

Phospholipid transfer protein (PLTP) participates in high density lipoprotein (HDL) metabolism. Increased plasma PLTP activity was observed in lipopolysaccharide (LPS) triggered acute inflammatory diseases. This study aimed to determine the exact role of PLTP in LPS induced inflammation. HDL pool size was shrunk both in PLTP deficient mice (PLTP-/-) and PLTP transgenic mice (PLTP-Tg). PLTP displayed a strong protective effect on lethal endotoxemia in mice survival study. Furthermore, after LPS stimulation, the expression of pro-inflammatory cytokines were increased in bone marrow derived macrophage (BMDM) from PLTP-/-, while decreased in BMDM from PLTP-Tg compared with BMDM from wild-type mice (WT). Moreover, LPS induced nuclear factor kappa-B (NFκB) activation was enhanced in PLTP-/- BMDM or PLTP knockdown RAW264.7. Conversely, PLTP overexpression countered the NFκB activation in LPS challenged BMDM. Additionally, the activation of toll like receptor 4 (TLR4) induced by LPS showed no alteration in PLTP-/- BMDM. Finally, PLTP could bind to LPS, attenuate the pro-inflammatory effects of LPS, and improve the cell viability in vitro. To sum up, these findings elucidated that PLTP repressed LPS induced inflammation due to extracellular LPS binding capability, and the protective effects were not related to HDL pool size in mice.

Dietary Blue Pigments Derived from Genipin, Attenuate Inflammation by Inhibiting LPS-Induced iNOS and COX-2 Expression via the NF-κB Inactivation

PubMed Central

Wang, Qiang-Song; Xiang, Yaozu; Cui, Yuan-Lu; Lin, Ke-Ming; Zhang, Xin-Fang

2012-01-01

Background and Purpose The edible blue pigments produced by gardenia fruits have been used as value-added colorants for foods in East Asia for 20 years. However, the biological activity of the blue pigments derived from genipin has not been reported. Methodology/Principal Findings The anti-inflammatory effect of blue pigments was studied in lipopolysaccharide (LPS) stimulated RAW 264.7 macrophage in vitro. The secretions of nitric oxide (NO) and prostaglandin E2 (PGE2) were inhibited in concentration-dependent manner by blue pigments. Real-time reverse-transcription polymerase chain reaction (Real-time RT-PCR) analyses demonstrated that the mRNA expression of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), interleukin (IL)-6, and tumor necrosis factor alpha (TNF-α) was inhibited, moreover, ELISA results showed that the productions of IL-6 and TNF-α were inhibited. Cell-based ELISA revealed the COX-2 protein expression was inhibited. The proteome profiler array showed that 12 cytokines and chemokines involved in the inflammatory process were down-regulated by blue pigments. Blue pigments inhibited the nuclear transcription factor kappa-B (NF-κB) activation induced by LPS, and this was associated with decreasing the DNA-binding activity of p65 and p50. Furthermore, blue pigments suppressed the degradation of inhibitor of κB (IκB) α, Inhibitor of NF-κB Kinase (IKK) α, IKK-β, and phosphorylation of IκB-α. The anti-inflammatory effect of blue pigments in vivo was studied in carrageenan-induced paw edema and LPS-injecting ICR mice. Finally, blue pigments significantly inhibited paw swelling and reduced plasma TNF-α and IL-6 production in vivo. Conclusions and Implications These results suggest that the anti-inflammatory properties of blue pigments might be the results from the inhibition of iNOS, COX-2, IL-6, IL-1β, and TNF-α expression through the down-regulation of NF-κB activation, which will provide strong scientific evidence for the

Forskolin Inhibits Lipopolysaccharide-Induced Modulation of MCP-1 and GPR120 in 3T3-L1 Adipocytes through an Inhibition of NFκB

PubMed Central

Chiadak, Jeanne Durendale; Arsenijevic, Tatjana; Verstrepen, Kevin; Gregoire, Françoise; Bolaky, Nargis; Delforge, Valérie; Flamand, Véronique

2016-01-01

In an obese state, Toll-like receptor-4 (TLR-4) upregulates proinflammatory adipokines secretion including monocyte chemotactic protein-1 (MCP-1) in adipose tissue. In contrast, G-protein coupled receptor 120 (GPR120) mediates antiobesity effects. The aim of this study was to determine the signaling pathway by which Forskolin (FK), a cyclic adenosine monophosphate- (cAMP-) promoting agent causing positive changes in body composition in overweight and obese adult men, affects MCP-1 and GPR120 expression during an inflammatory response induced by lipopolysaccharide (LPS) in adipocytes, such as in an obese state. 3T3-L1 cells differentiated into adipocytes (DC) were stimulated with LPS in the absence or presence of FK and inhibitors of TLR-4 and inhibitor of kappa B (IκBα). In DC, LPS increased MCP-1, TLR-4, and nuclear factor-κB1 (NFκB1) mRNA levels, whereas it decreased GPR120 mRNA levels. In DC, FK inhibited the LPS-induced increase in MCP-1, TLR-4, and NFκB1 mRNA levels and the LPS-induced decrease in GPR120 mRNA. BAY11-7082 and CLI-095 abolished these LPS-induced effects. In conclusion, FK inhibits LPS-induced increase in MCP-1 mRNA levels and decrease in GPR120 mRNA levels in adipocytes and may be a potential treatment for inflammation in obesity. Furthermore, TLR-4-induced activation of NFκB may be involved in the LPS-induced regulation of these genes. PMID:27881903

Forskolin Inhibits Lipopolysaccharide-Induced Modulation of MCP-1 and GPR120 in 3T3-L1 Adipocytes through an Inhibition of NFκB.

PubMed

Chiadak, Jeanne Durendale; Arsenijevic, Tatjana; Verstrepen, Kevin; Gregoire, Françoise; Bolaky, Nargis; Delforge, Valérie; Flamand, Véronique; Perret, Jason; Delporte, Christine

2016-01-01

In an obese state, Toll-like receptor-4 (TLR-4) upregulates proinflammatory adipokines secretion including monocyte chemotactic protein-1 (MCP-1) in adipose tissue. In contrast, G-protein coupled receptor 120 (GPR120) mediates antiobesity effects. The aim of this study was to determine the signaling pathway by which Forskolin (FK), a cyclic adenosine monophosphate- (cAMP-) promoting agent causing positive changes in body composition in overweight and obese adult men, affects MCP-1 and GPR120 expression during an inflammatory response induced by lipopolysaccharide (LPS) in adipocytes, such as in an obese state. 3T3-L1 cells differentiated into adipocytes (DC) were stimulated with LPS in the absence or presence of FK and inhibitors of TLR-4 and inhibitor of kappa B (I κ B α ). In DC, LPS increased MCP-1, TLR-4, and nuclear factor- κ B1 (NF κ B1) mRNA levels, whereas it decreased GPR120 mRNA levels. In DC, FK inhibited the LPS-induced increase in MCP-1, TLR-4, and NF κ B1 mRNA levels and the LPS-induced decrease in GPR120 mRNA. BAY11-7082 and CLI-095 abolished these LPS-induced effects. In conclusion, FK inhibits LPS-induced increase in MCP-1 mRNA levels and decrease in GPR120 mRNA levels in adipocytes and may be a potential treatment for inflammation in obesity. Furthermore, TLR-4-induced activation of NF κ B may be involved in the LPS-induced regulation of these genes.

Inhibition of insulin-like growth factor receptor-1 reduces necroptosis-related markers and attenuates LPS-induced lung injury in mice.

PubMed

Lee, Su Hwan; Shin, Ju Hye; Song, Joo Han; Leem, Ah Young; Park, Moo Suk; Kim, Young Sam; Chang, Joon; Chung, Kyung Soo

2018-04-15

Insulin-like growth factor-1 (IGF-1) levels are known to increase in the bronchoalveolar lavage fluid (BALF) of patients with acute respiratory distress syndrome. Herein, we investigated the role of IGF-1 in lipopolysaccharide (LPS)-induced lung injury. In LPS-treated cells, expressions of receptor-interacting protein 3 (RIP3) and phosphorylated mixed lineage kinase domain-like protein (MLKL) were decreased in IGF-1 receptor small interfering RNA (siRNA)-treated cells compared to control cells. The levels of pro-inflammatory cytokines including interleukin (IL)-1β, IL-6, IL-10, tumour necrosis factor-α, and macrophage inflammatory protein 2/C-X-C motif chemokine ligand 2 in the supernatant were significantly reduced in IGF-1 receptor siRNA-treated cells compared to control cells. In LPS-induced murine lung injury model, total cell counts, polymorphonuclear leukocytes counts, and pro-inflammatory cytokine levels in the BALF were significantly lower and histologically detected lung injury was less common in the group treated with IGF-1 receptor monoclonal antibody compared to the non-treated group. On western blotting, RIP3 and phosphorylated MLKL expressions were relatively decreased in the IGF-1 receptor monoclonal antibody group compared to the non-treated group. IGF-1 may be associated with RIP3-mediated necroptosis in vitro, while blocking of the IGF-1 pathway may reduce LPS-induced lung injuries in vivo. Copyright © 2018 Elsevier Inc. All rights reserved.

Copper chelation by tetrathiomolybdate inhibits lipopolysaccharide-induced inflammatory responses in vivo

PubMed Central

Wei, Hao; Beckman, Joseph S.; Zhang, Wei-Jian

2011-01-01

Redox-active transition metal ions, such as iron and copper, may play an important role in vascular inflammation, which is an etiologic factor in atherosclerotic vascular diseases. In this study, we investigated whether tetrathiomolybdate (TTM), a highly specific copper chelator, can act as an anti-inflammatory agent, preventing lipopolysaccharide (LPS)-induced inflammatory responses in vivo. Female C57BL/6N mice were daily gavaged with TTM (30 mg/kg body wt) or vehicle control. After 3 wk, animals were injected intraperitoneally with 50 μg LPS or saline buffer and killed 3 h later. Treatment with TTM reduced serum ceruloplasmin activity by 43%, a surrogate marker of bioavailable copper, in the absence of detectable hepatotoxicity. The concentrations of both copper and molybdenum increased in various tissues, whereas the copper-to-molybdenum ratio decreased, consistent with reduced copper bioavailability. TTM treatment did not have a significant effect on superoxide dismutase activity in heart and liver. Furthermore, TTM significantly inhibited LPS-induced inflammatory gene transcription in aorta and heart, including vascular and intercellular adhesion molecule-1 (VCAM-1 and ICAM-1, respectively), monocyte chemotactic protein-1 (MCP-1), interleukin-6, and tumor necrosis factor (TNF)-α (ANOVA, P < 0.05); consistently, protein levels of VCAM-1, ICAM-1, and MCP-1 in heart were also significantly lower in TTM-treated animals. Similar inhibitory effects of TTM were observed on activation of nuclear factor-κB (NF-κB) and activator protein-1 (AP-1) in heart and lungs. Finally, TTM significantly inhibited LPS-induced increases of serum levels of soluble ICAM-1, MCP-1, and TNF-α (ANOVA, P < 0.05). These data indicate that copper chelation with TTM inhibits LPS-induced inflammatory responses in aorta and other tissues of mice, most likely by inhibiting activation of the redox-sensitive transcription factors, NF-κB and AP-1. Therefore, copper appears to play an

The nuclear IkappaB protein IkappaBNS selectively inhibits lipopolysaccharide-induced IL-6 production in macrophages of the colonic lamina propria.

PubMed

Hirotani, Tomonori; Lee, Pui Y; Kuwata, Hirotaka; Yamamoto, Masahiro; Matsumoto, Makoto; Kawase, Ichiro; Akira, Shizuo; Takeda, Kiyoshi

2005-03-15

Macrophages play an important role in the pathogenesis of chronic colitis. However, it remains unknown how macrophages residing in the colonic lamina propria are regulated. We characterized colonic lamina proprial CD11b-positive cells (CLPMphi). CLPMphi of wild-type mice, but not IL-10-deficient mice, displayed hyporesponsiveness to TLR stimulation in terms of cytokine production and costimulatory molecule expression. We compared CLPMphi gene expression profiles of wild-type mice with IL-10-deficient mice, and identified genes that are selectively expressed in wild-type CLPMphi. These genes included nuclear IkappaB proteins such as Bcl-3 and IkappaBNS. Because Bcl-3 has been shown to specifically inhibit LPS-induced TNF-alpha production, we analyzed the role of IkappaBNS in macrophages. Lentiviral introduction of IkappaBNS resulted in impaired LPS-induced IL-6 production, but not TNF-alpha production in the murine macrophage cell line RAW264.7. IkappaBNS expression led to constitutive and intense DNA binding of NF-kappaB p50/p50 homodimers. IkappaBNS was recruited to the IL-6 promoter, but not to the TNF-alpha promoter, together with p50. Furthermore, small interference RNA-mediated reduction in IkappaBNS expression in RAW264.7 cells resulted in increased LPS-induced production of IL-6, but not TNF-alpha. Thus, IkappaBNS selectively suppresses LPS-induced IL-6 production in macrophages. This study established that nuclear IkappaB proteins differentially regulate LPS-induced inflammatory cytokine production in macrophages.

Fluoxetine up-regulates expression of cellular FLICE-inhibitory protein and inhibits LPS-induced apoptosis in hippocampus-derived neural stem cell

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chiou, S.-H.; Chen, S.-J.; Peng, C-H.

2006-05-05

Fluoxetine is a widely used antidepressant compound which inhibits the reuptake of serotonin in the central nervous system. Recent studies have shown that fluoxetine can promote neurogenesis and improve the survival rate of neurons. However, whether fluoxetine modulates the proliferation or neuroprotection effects of neural stem cells (NSCs) needs to be elucidated. In this study, we demonstrated that 20 {mu}M fluoxetine can increase the cell proliferation of NSCs derived from the hippocampus of adult rats by MTT test. The up-regulated expression of Bcl-2, Bcl-xL and the cellular FLICE-inhibitory protein (c-FLIP) in fluoxetine-treated NSCs was detected by real-time RT-PCR. Our resultsmore » further showed that fluoxetine protects the lipopolysaccharide-induced apoptosis in NSCs, in part, by activating the expression of c-FLIP. Moreover, c-FLIP induction by fluoxetine requires the activation of the c-FLIP promoter region spanning nucleotides -414 to -133, including CREB and SP1 sites. This effect appeared to involve the phosphatidylinositol-3-kinase-dependent pathway. Furthermore, fluoxetine treatment significantly inhibited the induction of proinflammatory factor IL-1{beta}, IL-6, and TNF-{alpha} in the culture medium of LPS-treated NSCs (p < 0.01). The results of high performance liquid chromatography coupled to electrochemical detection further confirmed that fluoxentine increased the functional production of serotonin in NSCs. Together, these data demonstrate the specific activation of c-FLIP by fluoxetine and indicate the novel role of fluoxetine for neuroprotection in the treatment of depression.« less

Effects of PPAR-γ agonist treatment on LPS-induced mastitis in rats.

PubMed

Mingfeng, Ding; Xiaodong, Ming; Yue, Liu; Taikui, Piao; Lei, Xiao; Ming, Liu

2014-12-01

PPAR-γ, a member of the nuclear receptor superfamily, plays an important role in lipid metabolism and inflammation. The aim of this study was to investigate the preventive effects of synthetic PPAR-γ agonist rosiglitazone on lipopolysaccharide (LPS)-induced mastitis in rats. The mouse model of mastitis was induced by the injection of LPS through the duct of the mammary gland. Rosiglitazone was injected 1 h before the induction of LPS intraperitoneally. The results showed that rosiglitazone attenuated the infiltration of inflammatory cells, the activity of myeloperoxidase (MPO), and the production of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and interleukin-1β (IL-1β) in a dose-dependent manner. Additionally, Western blotting showed that rosiglitazone inhibited the phosphorylation of IκB-α and NF-κB p65. These results indicated that rosiglitazone has a protective effect on mastitis, and the anti-inflammatory mechanism of rosiglitazone on LPS-induced mastitis in rats may be due to its ability to inhibit NF-κB signaling pathways. PPAR-γ may be a potential therapeutic target against mastitis.

AV119, a natural sugar from avocado gratissima, modulates the LPS-induced proinflammatory response in human keratinocytes.

PubMed

Donnarumma, Giovanna; Paoletti, Iole; Buommino, Elisabetta; Fusco, Alessandra; Baudouin, Caroline; Msika, Philippe; Tufano, Maria Antonietta; Baroni, Adone

2011-12-01

Keratinocytes play an active role in innate immune responses by secreting a variety of cytokines and chemokines. The release of critical proinflammatory cytokines, which are necessary to activate the immune response, is induced by the stimulation of Toll-like receptors (TLRs) by molecules present on pathogenic micro-organisms such as lipopolysaccharide (LPS). AV119, a patented blend of avocado sugars, induced the aggregation of Malassezia furfur, a dimorphic, lipid-dependent yeast that is part of the normal human cutaneous commensal flora and inhibited its penetration into the keratinocytes. In the present study, the anti-inflammatory effects of AV119 were investigated in LPS-induced inflammation of human keratinocytes. In particular, we analysed the modulation of the LPS-induced expression of proinflammatory cytokines and heat shock protein 70 (HSP70) by AV119 and the involvement of TLR-4. Our data show that AV119 is able to modulate significantly the proinflammatory response in human keratinocytes, blocking the NF-kB activation in human keratinocytes.

Suppression of LPS-induced inflammatory responses by the hydroxyl groups of dexamethasone

PubMed Central

Chuang, Ting-Yun; Cheng, An-Jie; Chen, I-Ting; Lan, Tien-Yun; Huang, I-Hsuan; Shiau, Chung-Wai; Hsu, Chia-Lin; Liu, Ya-Wen; Chang, Zee-Fen; Tseng, Ping-Hui; Kuo, Jean-Cheng

2017-01-01

The innate immune response is a central process that is activated during pathogenic infection in order to maintain physiological homeostasis. It is well known that dexamethasone (Dex), a synthetic glucocorticoid, is a potent immunosuppressant that inhibits the cytokine production induced by bacterial lipopolysaccharides (LPS). Nevertheless, the extent to which the functional groups of Dex control the excessive activation of inflammatory reactions remains unknown. Furthermore, importantly, the role of Dex in the innate immune response remains unclear. Here we explore the mechanism of LPS-induced TNF-α secretion and reveal p38 MAPK signaling as a target of Dex that is involved in control of tumor necrosis factor-α (TNF-α)-converting enzyme (TACE) activity; that later mediates the shedding of TNF-α that allows its secretion. We further demonstrate that the 11-hydroxyl and 21-hydroxyl groups of Dex are the main groups that are involved in reducing LPS-induced TNF-α secretion by activated macrophages. Blockage of the hydroxyl groups of Dex inhibits immunosuppressant effect of Dex during LPS-induced TNF-α secretion and mouse mortality. Our findings demonstrate Dex signaling is involved in the control of innate immunity. PMID:28537905

Glycolipids from spinach suppress LPS-induced vascular inflammation through eNOS and NK-κB signaling.

PubMed

Ishii, Masakazu; Nakahara, Tatsuo; Araho, Daisuke; Murakami, Juri; Nishimura, Masahiro

2017-07-01

Glycolipids are the major constituent of the thylakoid membrane of higher plants and have a variety of biological and pharmacological activities. However, anti-inflammatory effects of glycolipids on vascular endothelial cells have not been elucidated. Here, we investigated the effect of glycolipids extracted from spinach on lipopolysaccharides (LPS)-induced endothelial inflammation and evaluated the underlying molecular mechanisms. Treatment with glycolipids from spinach had no cytotoxic effects on cultured human umbilical vein endothelial cells (HUVECs) and significantly blocked the expression of LPS-induced interleukin (IL)-6, monocyte chemoattractant protein-1 (MCP-1), vascular cell adhesion molecule-1 (VCAM-1), and intracellular adhesion molecule-1 (ICAM-1) in them. Glycolipids treatment also effectively suppressed monocyte adhesion to HUVECs. Treatment with glycolipids inhibited LPS-induced NF-κB phosphorylation and nuclear translocation. In addition, glycolipids treatment significantly promoted endothelial nitric oxide synthase (eNOS) activation and nitric oxide (NO) production in HUVECs. Furthermore, glycolipids treatment blocked LPS-induced inducible NOS (iNOS) expression in HUVECs. Pretreatment with a NOS inhibitor attenuated glycolipids-induced suppression of NF-κB activation and adhesion molecule expression, and abolished the glycolipids-mediated suppression of monocyte adhesion to HUVECs. These results indicate that glycolipids suppress LPS-induced vascular inflammation through attenuation of the NF-κB pathway by increasing NO production in endothelial cells. These findings suggest that glycolipids from spinach may have a potential therapeutic use for inflammatory vascular diseases. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Inhibition of nitric oxide in LPS-stimulated macrophages of young and senescent mice by δ-tocotrienol and quercetin

PubMed Central

2011-01-01

increase in the production of NO, when LPS-stimulated macrophages of quercetin, δ-tocotrienol, or dexamethasone were also treated with IFN-β or IFN-γ compared to respective control groups. We also demonstrated that NO levels and iNOS mRNA expression levels were significantly higher in LPS-stimulated macrophages from senescent (0.69 vs 0.41; P < 0.05), compared to young mice. In contrast, age did not appear to impact levels of TNF-α protein or mRNA expression levels (0.38 vs 0.35) in LPS-stimulated macrophages. The histological analyses of livers of control groups showed lesions of peliosis and microvesicular steatosis, and treated groups showed Councilman body, and small or large lymphoplasmacytic clusters. Conclusions The present results demonstrated that quercetin and δ-tocotrienols inhibit the LPS-induced NO production in vivo. The microarray DNA analyses, followed by pathway analyses indicated that quercetin or δ-tocotrienol inhibit several LPS-induced expression of several ageing and pro-inflammatory genes (IL-1β, IL-1α, IL-6, TNF-α, IL-12, iNOS, VCAM1, ICAM1, COX2, IL-1RA, TRAF1 and CD40). The NF-κB pathway regulates the production of NO and inhibits the pro-inflammatory cytokines involved in normal and ageing process. These ex vivo results confirmed the earlier in vitro findings. The present findings of inhibition of NO production by quercetin and δ-tocotrienol may be of clinical significance treating several inflammatory diseases, including ageing process. PMID:22185406

Compound edaravone alleviates lipopolysaccharide (LPS)-induced acute lung injury in mice.

PubMed

Zhang, Zhengping; Luo, Zhaowen; Bi, Aijing; Yang, Weidong; An, Wenji; Dong, Xiaoliang; Chen, Rong; Yang, Shibao; Tang, Huifang; Han, Xiaodong; Luo, Lan

2017-09-15

Acute lung injury (ALI) represents an unmet medical need with an urgency to develop effective pharmacotherapies. Compound edaravone, a combination of edaravone and borneol, has been developed for treatment of ischemia stroke in clinical phase III study. The purpose of the present study is to investigate the anti-inflammatory effect of compound edaravone on lipopolysaccharide (LPS)-induced inflammatory response in RAW264.7 cells and the therapeutic efficacy on LPS-induced ALI in mice. Edaravone and compound edaravone concentration-dependently decreased LPS-induced interleukin-6 (IL-6) production and cyclooxygenase-2 (COX-2) expression in RAW264.7 cells. The efficiency of compound edaravone was stronger than edaravone alone. In the animal study, compound edaravone was injected intravenously to mice after intratracheal instillation of LPS. It remarkably alleviated LPS-induced lung injury including pulmonary histological abnormalities, polymorphonuclear leukocyte (PMN) infiltration and extravasation. Further study demonstrated that compound edaravone suppressed LPS-induced TNF-α and IL-6 increase in mouse serum and bronchoalveolar lavage (BAL) fluid, and inhibited LPS-induced nuclear factor-κB (NF-κB) activation and COX-2 expression in mice lung tissues. Importantly, our findings demonstrated that the compound edaravone showed a stronger protective effect against mouse ALI than edaravone alone, which suggested the synergies between edaravone and borneol. In conclusion, compound edaravone could be a potential novel therapeutic drug for ALI treatment and borneol might produce a synergism with edaravone. Copyright © 2017 Elsevier B.V. All rights reserved.

ST2 suppresses IL-6 production via the inhibition of I{kappa}B degradation induced by the LPS signal in THP-1 cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Takezako, Naoki; Hayakawa, Morisada; Hayakawa, Hiroko

2006-03-10

LPS induces the production of inflammatory cytokines via the stimulation of Toll-like receptors. In this study, we demonstrated that a soluble secreted form of the ST2 gene product (ST2), a member of the interleukin-1 receptor family, suppressed the production of IL-6 in an LPS-stimulated human monocytic leukemia cell line, THP-1. Immunofluorescence confocal microscopy revealed the binding of ST2 to the surface of the THP-1 cells, in which ST2 led to decreased binding of nuclear factor-{kappa}B to the IL-6 promoter. Furthermore, the degradation of I{kappa}B in the cytoplasm after LPS stimulation was reduced by pretreatment with ST2. These results demonstrated thatmore » ST2 negatively regulates LPS-induced IL-6 production via the inhibition of I{kappa}B degradation in THP-1 cells.« less

siRNA targeting mCD14 inhibits TNF-α, MIP-2, and IL-6 secretion and NO production from LPS-induced RAW264.7 cells.

PubMed

Lei, Ming; Jiao, Hanwei; Liu, Tao; Du, Li; Cheng, Ying; Zhang, Donglin; Hao, Yongchang; Man, Churiga; Wang, Fengyang

2011-10-01

Innate immunity plays a key role in protecting a host against invading microorganism, including Gram-negative bacteria. Cluster of differentiation antigen 14 (CD14) is an important innate immunity molecule, existing as a soluble (sCD14) and membrane-associated (mCD14) protein. Endotoxin [lipopolysaccharide (LPS)] is recognized as a key molecule in the pathogenesis of sepsis and septic shock caused by Gram negative bacteria. Emerging evidences indicate that upstream inhibition of bacterial LPS/Toll-like receptor 4(TLR4)/CD14-mediated inflammation pathway is an effective therapeutic approach for attenuating damaging immune activation. RNA interference (RNAi) provides a promising approach to down-regulate gene expression specifically. To explore the possibility of using RNAi against mCD14 as a strategy for inhibiting the secretion of cytokines and the nitric oxide (NO) production from LPS-activated RAW264.7 cells, four different short interfering RNA (siRNA) molecules corresponding to the sequence of mCD14 gene were designed and synthesized. We then tested the inhibition effects of these siRNA molecules on mCD14 expression by real-time quantitative RT-PCR and Western blot. After effective siRNA molecule (mCD14-siRNA-224), which is capable of reducing messenger RNA (mRNA) accumulation and protein expression of mCD14 specifically, was identified, RAW264.7 cells pretreated with mCD14-siRNA-224 were stimulated with LPS, and the secretion of tumor necrosis factor alpha (TNF-α), macrophage inflammatory protein-2 (MIP-2) and interleukin-6 (IL-6) and the NO production were evaluated. The results indicated that mCD14-siRNA-224 effectively inhibited TNF-α, MIP-2, and IL-6 release and NO production from LPS-stimulated RAW 264.7 cells by down-regulating mRNA accumulation and protein expression of mCD14 specifically. These findings provide useful information for the development of RNAi-based prophylaxis and therapy for endotoxin-related diseases.

Chlorogenic Acid Attenuates Lipopolysaccharide-Induced Acute Kidney Injury by Inhibiting TLR4/NF-κB Signal Pathway.

PubMed

Ye, Han-Yang; Jin, Jian; Jin, Ling-Wei; Chen, Yan; Zhou, Zhi-Hong; Li, Zhan-Yuan

2017-04-01

Chlorogenic acid (CGA), a polyphenolic compound, exists widely in medicinal herbs, which has been shown a strong antioxidant and anti-inflammatory effect. This study investigated the protective effects and mechanism of CGA on lipopolysaccharide (LPS)-induced acute kidney injury (AKI). Treatment of CGA successfully ameliorates LPS-induced renal function and pathological damage. Moreover, CGA dose-dependently suppressed LPS-induced blood urea nitrogen (BUN), creatinine levels, and inflammatory cytokines TNF-α, IL-6, and IL-1β in serum and tissue. The relative proteins' expression of TLR4/NF-κB signal pathway was assessed by western blot analysis. Our results showed that CGA dose-dependently attenuated LPS-induced kidney histopathologic changes, serum BUN, and creatinine levels. CGA also suppressed LPS-induced TNF-α, IL-6, and IL-1β production both in serum and kidney tissues. Furthermore, our results showed that CGA significantly inhibited the LPS-induced expression of phosphorylated NF-κB p65 and IκB as well as the expression of TLR4 signal. In conclusion, our results provide a mechanistic explanation for the anti-inflammatory effects of CGA in LPS-induced AKI mice through inhibiting TLR4/NF-κB signaling pathway.

The alpha2-adrenoreceptor agonist dexmedetomidine protects against lipopolysaccharide-induced apoptosis via inhibition of gap junctions in lung fibroblasts.

PubMed

Zhang, Yuan; Tan, Xiaoming; Xue, Lianfang

2018-01-01

The α2-adrenoceptor inducer dexmedetomidine protects against acute lung injury (ALI), but the mechanism of this effect is largely unknown. The present study investigated the effect of dexmedetomidine on apoptosis induced by lipopolysaccharide (LPS) and the relationship between this effect and gap junction intercellular communication in human lung fibroblast cell line. Flow cytometry was used to detect apoptosis induced by LPS. Parachute dye coupling assay was used to measure gap junction function, and western blot analysis was used to determine the expression levels of connexin43 (Cx43). The results revealed that exposure of human lung fibroblast cell line to LPS for 24 h increased the apoptosis, and pretreatment of dexmedetomidine and 18α-GA significantly reduced LPS-induced apoptosis. Dexmedetomidine exposure for 1 h inhibited gap junction function mainly via a decrease in Cx43 protein levels in human lung fibroblast cell line. These results demonstrated that the inhibition of gap junction intercellular communication by dexmedetomidine affected the LPS-induced apoptosis through inhibition of gap junction function by reducing Cx43 protein levels. The present study provides evidence of a novel mechanism underlying the effects of analgesics in counteracting ALI. Copyright © 2017 Elsevier Inc. All rights reserved.

The disintegrin, trimucrin, suppresses LPS-induced activation of phagocytes primarily through blockade of NF-κB and MAPK activation.

PubMed

Hung, Yu-Chun; Hsu, Chun-Chieh; Chung, Ching-Hu; Huang, Tur-Fu

2016-07-01

In addition to antiplatelet activity, disintegrin, a small-mass RGD-containing polypeptide, has been shown to exert anti-inflammatory effects but the mechanism involved remains unclear. In this study, we report that trimucrin, a disintegrin from the venom of Trimeresurus mucrosquamatus, inhibits lipopolysaccharide (LPS)-induced stimulation of THP-1 and RAW 264.7 cells. We also investigate the underlying mechanism. Trimucrin decreased the release of proinflammatory cytokines including tumor necrosis factor α (TNFα), interleukin-6 (IL-6), nitric oxide, and reactive oxygen species (ROS), and inhibited the adhesion and migration of LPS-activated phagocytes. Trimucrin significantly blocked the expression of nuclear factor kappaB (NF-κB)-related downstream inducible enzymes such as inducible nitric oxide synthase (iNOS) and COX-2. In addition, its anti-inflammatory effect was associated with the decreased mitogen-activated protein kinase (MAPK) phosphorylation. Furthermore, trimucrin concentration dependently inhibited LPS-induced phosphorylation of focal adhesion kinase (FAK), PI3K, and Akt. Trimucrin also reversed the DNA-binding activity of NF-κB by suppressing the LPS-induced nuclear translocation of p65 and the cytosolic IκB release. Flow cytometric analyses showed that trimucrin bound to cells in a concentration-dependent manner. The anti-αVβ3 mAb also specifically decreased the binding of fluorescein isothiocyanate (FITC)-conjugated trimucrin. Binding assays demonstrated that integrin αVβ3 was the binding site for trimucrin on THP-1 and RAW 264.7 cells. In conclusion, we showed that trimucrin decreases the inflammatory reaction through the attenuation of iNOS expression and nitric oxide (NO) production by blocking MAP kinase and the NF-κB activation in LPS-stimulated THP-1 and RAW 264.7 cells.

PPAR-α Agonist WY-14643 Inhibits LPS-Induced Inflammation in Synovial Fibroblasts via NF-kB Pathway.

PubMed

Huang, Degang; Zhao, Quanlai; Liu, Hongfei; Guo, Yongjie; Xu, Hongguang

2016-08-01

Osteoarthritis (OA), the most prevalent form of arthritis that results from breakdown of joint cartilage and underlying bone, has been viewed as a chronic condition manifested by persistence of inflammatory responses and infiltration of lymphocytes. Regulation of the inflammatory responses in synovial fibroblasts might be useful to prevent the development and deterioration of osteoarthritis. WY-14643, a potent peroxisome proliferator activator receptor-α (PPAR-α) agonist, has been described to beneficially regulate inflammation in many mammalian cells. Here, we investigate the potential anti-inflammatory role of WY-14643 in lipopolysaccharide (LPS)-induced synovial fibroblasts. WY-14643 greatly inhibited the production of NO and PGE2 induced by LPS. In addition, the mRNA expression of intracellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), endothelin-1 (ET-1), and tissue factor (TF) was significantly suppressed by WY-14643, as well as the secretion of pro-inflammatory cytokines including interleukin-6 (IL-6), IL-1β, tumor necrosis factor-α (TNF-α), and monocyte chemotactic protein-1 (MCP-1). Furthermore, the transcription activity and nuclear translocation of NF-kB were found to be markedly decreased by WY-14643, while the phosphorylation of IkB was enhanced, indicating that the anti-inflammatory role of WY-14643 was meditated by NF-kB-dependent pathway. The application of WY-14643 failed to carry out its anti-inflammatory function in PPAR-α silenced cells, suggesting the role of PPAR-α. These findings may facilitate further studies investigating the translation of pharmacological PPAR-α activation into clinical therapy of OA.

LPS-inducible factor(s) from activated macrophages mediates cytolysis of Naegleria fowleri amoebae

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cleary, S.F.; Marciano-Cabral, F.

1986-03-01

Soluble cytolytic factors of macrophage origin have previously been described with respect to their tumoricidal activity. The purpose of this study was to investigate the mechanism and possible factor(s) responsible for cytolysis of the amoeba Naegleria fowleri by activated peritoneal macrophages from B6C3F1 mice. Macrophages or conditioned medium (CM) from macrophage cultures were incubated with /sup 3/H-Uridine labeled amoebae. Percent specific release of label served as an index of cytolysis. Bacille Calmette-Guerin (BCG) and Corynebacterium parvum macrophages demonstrated significant cytolysis of amoebae at 24 h with an effector to target ratio of 10:1. Treatment of macrophages with inhibitors of RNAmore » or protein synthesis blocked amoebicidal activity. Interposition of a 1 ..mu..m pore membrane between macrophages and amoebae inhibited killing. Inhibition in the presence of the membrane was overcome by stimulating the macrophages with LPS. CM from SPS-stimulated, but not unstimulated, cultures of activated macrophages was cytotoxic for amoebae. The activity was heat sensitive and was recovered from ammonium sulfate precipitation of the CM. Results indicate that amoebicidal activity is mediated by a protein(s) of macrophage origin induced by target cell contact or stimulation with LPS.« less

Formononetin inhibited the inflammation of LPS-induced acute lung injury in mice associated with induction of PPAR gamma expression.

PubMed

Ma, Zhanqiang; Ji, Weiwei; Fu, Qiang; Ma, Shiping

2013-12-01

Formononetin has shown a variety of pharmacologic properties including anti-inflammatory effect. In the present study, we analyzed the role of formononetin in acute lung injury induced by lipopolysaccharide (LPS) in mice. The cell counting in the bronchoalveolar lavage fluid (BALF) was measured. The animal lung edema degree was evaluated by wet/dry weight ratio. The superoxidase dismutase (SOD) activity and myeloperoxidase (MPO) activity was assayed by SOD and MPO kits, respectively. The levels of inflammatory mediators, tumor necrosis factor-α (TNF-α) and IL-6,were assayed by enzyme-linked immunosorbent assay method. Pathological changes of hung tissues were observed by HE staining. Peroxisome proliferator-activated receptor (PPAR)-γ gene expression was measured by real-time PCR. The data showed that treatment with the formononetin group markedly attenuated inflammatory cell numbers in the BALF, increased PPAR-γ gene expression and improved SOD activity and inhibited MPO activity. The histological changes of the lungs were also significantly improved by formononetin compared to LPS group. The results indicated that formononetin has a protective effect on LPS-induced acute lung injury in mice.

Requirement for STAT1 in LPS-induced gene expression in macrophages.

PubMed

Ohmori, Y; Hamilton, T A

2001-04-01

This study examines the role of the signal transducer and activator of transcription 1 (STAT1) in induction of lipopolysaccharide (LPS)-stimulated gene expression both in vitro and in vivo. LPS-induced expression of an interferon (IFN)-inducible 10-kDa protein (IP-10), IFN regulatory factor-1 (IRF-1), and inducible nitric oxide synthase (iNOS) mRNAs was severely impaired in macrophages prepared from Stat1-/- mice, whereas levels of tumor necrosis factor alpha and KC (a C-X-C chemokine) mRNA in LPS-treated cell cultures were unaffected. A similar deficiency in LPS-induced gene expression was observed in livers and spleens from Stat1-/- mice. The reduced LPS-stimulated gene expression seen in Stat1-/- macrophages was not the result of reduced activation of nuclear factor kappaB. LPS stimulated the delayed activation of both IFN-stimulated response element and IFN-gamma-activated sequence binding activity in macrophages from wild-type mice. Activation of these STAT1-containing transcription factors was mediated by the intermediate induction of type I IFNs, since the LPS-induced IP-10, IRF-1, and iNOS mRNA expression was markedly reduced in macrophages from IFN-alpha/betaR-/- mice and blocked by cotreatment with antibodies against type I IFN. These results indicate that indirect activation of STAT1 by LPS-induced type I IFN participates in promoting optimal expression of LPS-inducible genes, and they suggest that STAT1 may play a critical role in innate immunity against gram-negative bacterial infection.

Chamomile: an anti-inflammatory agent inhibits inducible nitric oxide synthase expression by blocking RelA/p65 activity.

PubMed

Bhaskaran, Natarajan; Shukla, Sanjeev; Srivastava, Janmejai K; Gupta, Sanjay

2010-12-01

Chamomile has long been used in traditional medicine for the treatment of inflammation-related disorders. In this study we investigated the inhibitory effects of chamomile on nitric oxide (NO) production and inducible nitric oxide synthase (iNOS) expression, and explored its potential anti-inflammatory mechanisms using RAW 264.7 macrophages. Chamomile treatment inhibited LPS-induced NO production and significantly blocked IL-1β, IL-6 and TNFα-induced NO levels in RAW 264.7 macrophages. Chamomile caused reduction in LPS-induced iNOS mRNA and protein expression. In RAW 264.7 macrophages, LPS-induced DNA binding activity of RelA/p65 was significantly inhibited by chamomile, an effect that was mediated through the inhibition of IKKβ, the upstream kinase regulating NF-κB/Rel activity, and degradation of inhibitory factor-κB. These results demonstrate that chamomile inhibits NO production and iNOS gene expression by inhibiting RelA/p65 activation and supports the utilization of chamomile as an effective anti-inflammatory agent.

Attenuation of LPS-induced inflammation by ICT, a derivate of icariin, via inhibition of the CD14/TLR4 signaling pathway in human monocytes.

PubMed

Wu, Jinfeng; Zhou, Junmin; Chen, Xianghong; Fortenbery, Nicole; Eksioglu, Erika A; Wei, Sheng; Dong, Jingcheng

2012-01-01

To evaluate the anti-inflammatory potential of ICT in LPS stimulated human innate immune cells. 3, 5, 7-Trihydroxy-4'-methoxy-8-(3-hydroxy-3- methylbutyl)-flavone (ICT) is a novel derivative of icariin, the major active ingredient of Herba Epimedii, an herb used in traditional Chinese medicine. We previously demonstrated its anti-inflammatory potential in a murine macrophage cell line as well as in mouse models. We measured TNF-α production by ELISA, TLR4/CD14 expression by flow cytometry, and NF-κB and MAPK activation by western blot all in LPS-stimulated PBMC, human monocytes, or THP-1 cells after treatment with ICT. ICT inhibited LPS-induced TNF-α production in THP-1 cells, PBMCs and human monocytes in a dose-dependent manner. ICT treatment resulted in down-regulation of the expression of CD14/TLR4 and attenuated NF-κB and MAPK activation induced by LPS. We illustrate the anti-inflammatory property of ICT in human immune cells, especially in monocytes. These effects were mediated, at least partially, via inhibition of the CD14/TLR4 signaling pathway. Copyright © 2011 Elsevier B.V. All rights reserved.

Eupafolin inhibits PGE2 production and COX2 expression in LPS-stimulated human dermal fibroblasts by blocking JNK/AP-1 and Nox2/p47{sup phox} pathway

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tsai, Ming-Horng; Lin, Zih-Chan; Liang, Chan-Jung

2014-09-01

Eupafolin, a major active component found in the methanol extracts of Phyla nodiflora, has been used to treat inflammation of skin. We examined its effects on cyclooxygenase-2 (COX-2) expression in LPS-treated human dermal fibroblasts. Lipopolysaccharide (LPS) significantly increased prostaglandin-E2 (PGE2) production associated with increased COX-2 expression in Hs68 cells. This effect was blocked by eupafolin, TLR-4 antibody, antioxidants (APO and NAC), as well as inhibitors, including U0126 (ERK1/2), SB202190 (p38), SP600125 (JNK1/2), and Tanshinone IIA (AP-1). In gene regulation level, qPCR and promoter assays revealed that COX-2 expression was attenuated by eupafolin. In addition, eupafolin also ameliorated LPS-induced p47 phoxmore » activation and decreased reactive oxygen species (ROS) generation and NADPH oxidase (Nox) activity. Moreover, pretreatment with eupafolin and APO led to reduced LPS-induced phosphorylation of ERK1/2, JNK, and p38. Further, eupafolin attenuated LPS-induced increase in AP-1 transcription factor binding activity as well as the increase in the phosphorylation of c-Jun and c-Fos. In vivo studies have shown that in dermal fibroblasts of LPS treated mice, eupafolin exerted anti-inflammation effects by decreasing COX-2 protein levels. Our results reveal a novel mechanism for anti-inflammatory and anti-oxidative effects of eupafolin that involved inhibition of LPS-induced ROS generation, suppression of MAPK phosphorylation, diminished DNA binding activity of AP-1 and attenuated COX-2 expression leading to reduced production of prostaglandin E2 (PGE2). Our results demonstrate that eupafolin may be used to treat inflammatory responses associated with dermatologic diseases. - Highlights: • LPS activates the Nox2/p47{sup phox}/JNK/AP-1 and induces COX2 expression in Hs68 cells. • Eupafolin inhibits LPS-induced COX-2 expression via Nox2/p47{sup phox} inhibition. • Eupafolin may be used in the treatment of skin diseases involving

Sulforaphane suppressed LPS-induced inflammation in mouse peritoneal macrophages through Nrf2 dependent pathway.

PubMed

Lin, Wen; Wu, Rachel T; Wu, Tienyuan; Khor, Tin-Oo; Wang, Hu; Kong, Ah-Ng

2008-10-15

Sulforaphane (SFN) is a natural isothiocyanate that is present in cruciferous vegetables such as broccoli and cabbage. Previous studies have shown that SFN is effective in preventing carcinogenesis induced by carcinogens in rodents, which is related in part to its potent anti-inflammation properties. In the present study, we compared the anti-inflammatory effect of SFN on LPS-stimulated inflammation in primary peritoneal macrophages derived from Nrf2 (+/+) and Nrf2 (-/-) mice. Pretreatment of SFN in Nrf2 (+/+) primary peritoneal macrophages potently inhibited LPS-stimulated mRNA expression, protein expression and production of TNF-alpha, IL-1beta, COX-2 and iNOS. HO-1 expression was significantly augmented in LPS-stimulated Nrf2 (+/+) primary peritoneal macrophages by SFN. Interestingly, the anti-inflammatory effect was attenuated in Nrf2 (-/-) primary peritoneal macrophages. We concluded that SFN exerts its anti-inflammatory activity mainly via activation of Nrf2 in mouse peritoneal macrophages.

Common bean (Phaseolus vulgaris L.) hydrolysates inhibit inflammation in LPS-induced macrophages through suppression of NF-κB pathways.

PubMed

Oseguera-Toledo, Miguel E; de Mejia, Elvira Gonzalez; Dia, Vermont P; Amaya-Llano, Silvia L

2011-08-01

The objectives of this study were to evaluate the antioxidant capacity of protein hydrolysates of the common bean (Phaseolus vulgaris L.) varieties Negro 8025 and Pinto Durango and determine their effect on the markers of inflammation in lipopolysaccharide (LPS)-induced RAW 264.7 macrophages. Cell viability was determined and the percentage of viable cells was calculated and concentrations that allowed >80% cell viability were used to determine the markers of inflammation. Alcalase hydrolysates and pepsin-pancreatin hydrolysates showed the highest antioxidant capacity after 80 and 120min of hydrolysis, respectively. Alcalase hydrolysates of the common bean Pinto Durango at 120min inhibited inflammation, with IC50 values of 34.9±0.3, 13.9±0.3, 5.0±0.1 and 3.7±0.2μM, while var. Negro needed 43.6±0.2, 61.3±0.3, 14.2±0.3 and 48.2±0.1μM for the inhibition of cyclooxygenase-2 expression, prostaglandin E2 production, inducible nitric oxide synthase expression and nitric oxide production, respectively. Also, hydrolysates significantly inhibited the transactivation of NF-κB and the nuclear translocation of the NF-κB p65 subunit. In conclusion, hydrolysates from the common bean can be used to combat inflammatory and oxidative-associated diseases. Copyright © 2011 Elsevier Ltd. All rights reserved.

Inhibition of LPS binding to MD-2 co-receptor for suppressing TLR4-mediated expression of inflammatory cytokine by 1-dehydro-10-gingerdione from dietary ginger

DOE Office of Scientific and Technical Information (OSTI.GOV)

Park, Sun Hong; Kyeong, Min Sik; Hwang, Yuri

Highlights: Black-Right-Pointing-Pointer 1-Dehydro-10-gingerdione (1D10G) from ginger inhibits LPS binding to MD-2. Black-Right-Pointing-Pointer 1D10G suppresses MyD88- or TRIF-dependent signaling in LPS-activated macrophages. Black-Right-Pointing-Pointer 1D10G down-regulates the expression of NF-{kappa}B-, AP1- or IRF3-target genes. Black-Right-Pointing-Pointer MD-2 is a molecular target in the anti-inflammatory action of 1D10G. -- Abstract: Myeloid differentiation protein 2 (MD-2) is a co-receptor of toll-like receptor 4 (TLR4) for innate immunity. Here, we delineated a new mechanism of 1-dehydro-10-gingerdione (1D10G), one of pungent isolates from ginger (Zingiber officinale), in the suppression of lipopolysaccharide (LPS)-induced gene expression of inflammatory cytokines. 1D10G inhibited LPS binding to MD-2 with higher affinity thanmore » gingerol and shogaol from dietary ginger. Moreover, 1D10G down-regulated TLR4-mediated expression of nuclear factor-{kappa}B (NF-{kappa}B) or activating protein 1 (AP1)-target genes such as tumor necrosis factor {alpha} (TNF-{alpha}) and interleukin-1{beta}, as well as those of interferon (IFN) regulatory factor 3 (IRF3)-target IFN-{beta} gene and IFN-{gamma} inducible protein 10 (IP-10) in LPS-activated macrophages. Taken together, MD-2 is a molecular target in the anti-inflammatory action of 1D10G.« less

Anti-inflammatory action of high molecular weight Mytilus edulis hydrolysates fraction in LPS-induced RAW264.7 macrophage via NF-κB and MAPK pathways.

PubMed

Kim, Young-Sang; Ahn, Chang-Bum; Je, Jae-Young

2016-07-01

Anti-inflammatory Mytilus edulis hydrolysates (MEHs) were prepared by peptic hydrolysis and MEH was further fractionated into three fractions based on molecular weight, namely >5kDa, 1-5kDa, and <1kDa. The >5kDa peptide fraction exerted the highest nitric oxide (NO) inhibitory activity and inhibited prostaglandin E2 (PGE2) secretion in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages. Pretreatment with the >5kDa peptide fraction markedly inhibited LPS-stimulated inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) protein and gene expressions. Stimulation by LPS induced the production of pro-inflammatory cytokines, such as tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and -1β (IL-1β), whereas co-treatment with the >5kDa peptide fraction suppressed pro-inflammatory cytokine production. The >5kDa peptide fraction inhibited the translocation of NF-κB (nuclear factor-kappa B) through the prevention of IκBα (inhibitory factor kappa B alpha) phosphorylation and degradation and also inhibited the MAPK signaling pathway in LPS-stimulated RAW264.7 macrophages. Copyright © 2016 Elsevier Ltd. All rights reserved.

GSK-3Beta-Dependent Activation of GEF-H1/ROCK Signaling Promotes LPS-Induced Lung Vascular Endothelial Barrier Dysfunction and Acute Lung Injury.

PubMed

Yi, Lei; Huang, Xiaoqin; Guo, Feng; Zhou, Zengding; Chang, Mengling; Huan, Jingning

2017-01-01

The bacterial endotoxin or lipopolysaccharide (LPS) leads to the extensive vascular endothelial cells (EC) injury under septic conditions. Guanine nucleotide exchange factor-H1 (GEF-H1)/ROCK signaling not only involved in LPS-induced overexpression of pro-inflammatory mediator in ECs but also implicated in LPS-induced endothelial hyper-permeability. However, the mechanisms behind LPS-induced GEF-H1/ROCK signaling activation in the progress of EC injury remain incompletely understood. GEF-H1 localized on microtubules (MT) and is suppressed in its MT-bound state. MT disassembly promotes GEF-H1 release from MT and stimulates downstream ROCK-specific GEF activity. Since glycogen synthase kinase (GSK-3beta) participates in regulating MT dynamics under pathologic conditions, we examined the pivotal roles for GSK-3beta in modulating LPS-induced activation of GEF-H1/ROCK, increase of vascular endothelial permeability and severity of acute lung injury (ALI). In this study, we found that LPS induced human pulmonary endothelial cell (HPMEC) monolayers disruption accompanied by increase in GSK-3beta activity, activation of GEF-H1/ROCK signaling and decrease in beta-catenin and ZO-1 expression. Inhibition of GSK-3beta reduced HPMEC monolayers hyper-permeability and GEF-H1/ROCK activity in response to LPS. GSK-3beta/GEF-H1/ROCK signaling is implicated in regulating the expression of beta-catenin and ZO-1. In vivo , GSK-3beta inhibition attenuated LPS-induced activation of GEF-H1/ROCK pathway, lung edema and subsequent ALI. These findings present a new mechanism of GSK-3beta-dependent exacerbation of lung micro-vascular hyper-permeability and escalation of ALI via activation of GEF-H1/ROCK signaling and disruption of intracellular junctional proteins under septic condition.

Inhibition of Neddylation Represses Lipopolysaccharide-induced Proinflammatory Cytokine Production in Macrophage Cells

PubMed Central

Chang, Fang-Mei; Reyna, Sara M.; Granados, Jose C.; Wei, Sung-Jen; Innis-Whitehouse, Wendy; Maffi, Shivani K.; Rodriguez, Edward; Slaga, Thomas J.; Short, John D.

2012-01-01

Cullin-RING E3 ligases (CRLs) are a class of ubiquitin ligases that control the proteasomal degradation of numerous target proteins, including IκB, and the activity of these CRLs are positively regulated by conjugation of a Nedd8 polypeptide onto Cullin proteins in a process called neddylation. CRL-mediated degradation of IκB, which normally interacts with and retains NF-κB in the cytoplasm, permits nuclear translocation and transactivation of the NF-κB transcription factor. Neddylation occurs through a multistep enzymatic process involving Nedd8 activating enzymes, and recent studies have shown that the pharmacological agent, MLN4924, can potently inhibit Nedd8 activating enzymes, thereby preventing neddylation of Cullin proteins and preventing the degradation of CRL target proteins. In macrophages, regulation of NF-κB signaling functions as a primary pathway by which infectious agents such as lipopolysaccharides (LPSs) cause the up-regulation of proinflammatory cytokines. Here we have analyzed the effects of MLN4924, and compared the effects of MLN4924 with a known anti-inflammatory agent (dexamethasone), on certain proinflammatory cytokines (TNF-α and IL-6) and the NF-κB signaling pathway in LPS-stimulated macrophages. We also used siRNA to block neddylation to assess the role of this molecular process during LPS-induced cytokine responsiveness. Our results demonstrate that blocking neddylation, either pharmacologically or using siRNA, abrogates the increase in certain proinflammatory cytokines secreted from macrophages in response to LPS. In addition, we have shown that MLN4924 and dexamethasone inhibit LPS-induced cytokine up-regulation at the transcriptional level, albeit through different molecular mechanisms. Thus, neddylation represents a novel molecular process in macrophages that can be targeted to prevent and/or treat the LPS-induced up-regulation of proinflammatory cytokines and the disease processes associated with their up-regulation. PMID

Neochlorogenic acid inhibits against LPS-activated inflammatory responses through up-regulation of Nrf2/HO-1 and involving AMPK pathway.

PubMed

Park, Sun Young; Jin, Mei Ling; Yi, Eun Hye; Kim, Yoon; Park, Geuntae

2018-06-08

Acute and chronic inflammatory diseases are associated with excessive inflammation due to the accumulation of pro-inflammatory mediators and cytokines produced by macrophages. In the present study, we investigated the anti-inflammatory properties of neochlorogenic acid (nCGA) from Lonicera japonica on lipopolysaccharide (LPS)-activated inflammation in macrophages and participation of the AMPK/Nrf2 pathway. nCGA pretreatment significantly reduced the production of nitric oxide, prostaglandin E 2 , TNF-α, reactive oxygen species, IL-1β, and IL-6 by LPS-activated macrophages. Moreover, both transcript and protein levels of inducible nitric oxide synthase and cyclooxygenase-2 were reduced by nCGA in LPS-activated macrophages. nCGA inhibited NF-κB activation by attenuating IKKα/β and IκBα phosphorylation in LPS-stimulated macrophages. Moreover, nCGA attenuated LPS-elevated JAK-1, STAT-1, and MAPK phosphorylation. We further evaluated the possible role of nCGA in the induction of AMPK/Nrf2 signal pathways required for the protein expression of HO-1 and NQO-1. nCGA induced AMPK activation via phosphorylation of LKB1 and CaMKII and by the inhibitory phosphorylation of GSK3β. It stimulated the overexpression of Nrf2/ARE-regulated downstream proteins, such as NQO-1 and HO-1. Furthermore, the anti-inflammatory effects of nCGA were attenuated in macrophages subjected to siRNAs specific for HO-1, NQO-1, Nrf2, and AMPK. Accordingly, these results indicate that nCGA, as an AMPK/Nrf2 signal activator, prevents excessive macrophage-mediated responses associated with acute and chronic inflammatory disorders. Copyright © 2018 Elsevier B.V. All rights reserved.

Protective effect of Jolkinolide B on LPS-induced mouse acute lung injury.

PubMed

Yang, Hailing; Li, Yan; Huo, Pengfei; Li, Xiao-Ou; Kong, Daliang; Mu, Wei; Fang, Wei; Li, Lingxia; Liu, Ning; Fang, Ling; Li, Hongjun; He, Chengyan

2015-05-01

Jolkinolide B (JB), an ent-abietane diterpenoid, isolated from the dried root of Euphorbia fischeriana, has been reported to have potent anti-tumor and anti-inflammatory activities. However, the effects of JB on acute lung injury (ALI) and underlying molecular mechanisms have not been investigated. The present study aimed to investigate the effect of JB on lipopolysaccharide (LPS)-induced ALI. Male C57BL/6 mice were pretreated with dexamethasone or JB 1h before intranasal instillation of LPS. The results showed that JB markedly attenuated LPS-induced histological alterations, lung edema, inflammatory cell infiltration, myeloperoxidase (MPO) activity as well as the production of TNF-α, IL-6 and IL-1β. Furthermore, JB also significantly inhibited LPS-induced the degradation of IκBα and phosphorylation of NF-κB p65 and MAPK. Therefore, our study provides the first line of evidence that pretreatment of JB has a protective effect on LPS-induced ALI in mice. The anti-inflammatory mechanism of JB may be attributed to its suppression of NF-κB and MAPK activation. Copyright © 2015 Elsevier B.V. All rights reserved.

Sulforaphane suppressed LPS-induced inflammation in mouse peritoneal macrophages through Nrf2 dependent pathway

PubMed Central

Lin, Wen; Wu, Rachel T; Wu, Tienyuan; Khor, Tin-Oo; Wang, Hu; Kong, Ah-Ng

2008-01-01

Sulforaphane (SFN) is a natural isothiocyanate that is present in cruciferous vegetables such as broccoli and cabbage. Previous studies have shown that SFN is effective in preventing carcinogenesis induced by carcinogens in rodents, which is related in part to its potent anti-inflammation properties. In the present study, we compared the anti-inflammatory effect of SFN on LPS-stimulated inflammation in primary peritoneal macrophages derived from Nrf2 (+/+) and Nrf2 mice. Pretreatment of SFN in Nrf2 (+/+) primary peritoneal macrophages potently inhibited LPS-stimulated mRNA expression, protein expression and production of TNFα, IL-1β, Cox-2 and iNOS. HO-1 expression, which is significantly augmented in LPS-stimulated Nrf2 (+/+) primary peritoneal macrophages by SFN. Interestingly, the anti-inflammatory effect was attenuated in Nrf2 (−/−) primary peritoneal macrophages. We concluded that SFN exerts its anti-inflammatory activity mainly via activation of Nrf2 in mouse peritoneal macrophages. PMID:18755157

Chamomile, an anti-inflammatory agent inhibits inducible nitric oxide synthase expression by blocking RelA/p65 activity

PubMed Central

Bhaskaran, Natarajan; Shukla, Sanjeev; Srivastava, Janmejai K; Gupta, Sanjay

2010-01-01

Chamomile has long been used in traditional medicine for the treatment of inflammation-related disorders. In this study we aimed to investigate the inhibitory effects of chamomile on nitric oxide (NO) production and inducible nitric oxide synthase (iNOS) expression, and to explore its potential anti-inflammatory mechanisms using RAW 264.7 macrophages. Chamomile treatment inhibited LPS-induced NO production and significantly blocked IL-1β , IL-6 and TNFα-induced NO levels in RAW 264.7 macrophages. Chamomile caused reduction in LPS-induced iNOS mRNA and protein expression. In RAW 264.7 macrophages, LPS-induced DNA binding activity of RelA/p65 was significantly inhibited by chamomile, an effect that was mediated through the inhibition of IKKβ , the upstream kinase regulating NF-κ B/Rel activity, and degradation of inhibitory factor-κ B. These results demonstrate that chamomile inhibits NO production and iNOS gene expression by inhibiting RelA/p65 activation and supports the utilization of chamomile as an effective anti-inflammatory agent. PMID:21042790

CD200Fc reduces LPS-induced IL-1β activation in human cervical cancer cells by modulating TLR4-NF-κB and NLRP3 inflammasome pathway.

PubMed

He, Aiqin; Shao, Jia; Zhang, Yu; Lu, Hong; Wu, Zhijun; Xu, Yunzhao

2017-05-16

Chronic inflammation plays an important role in tumorigenesis of cervical cancer. CD200Fc, a CD200R1 agonist, has been found to have anti-inflammatory effects in autoimmune diseases and neuro-degeneration. However, the anti-inflammatory effect of CD200Fc on cervical cancer has not yet to be completely understood. This study investigated the anti-inflammatory effects and mechanisms of CD200Fc in LPS-induced human SiHa cells and Caski cells. SiHa cells and Caski cells were stimulated with 40 μg/ml LPS under different concentrations of CD200Fc for 90 min or 12 hours. The mRNA and protein levels of pro-IL-1β, cleaved-IL-1β and NLRP3, as well as the protein level of cleaved caspase-1, were significantly increased in LPS-induced SiHa cells and Caski cells. LPS stimulation did not change ASC and pro-caspase-1 expression. CD200Fc down-regulated protein expression of cleaved caspase-1 and mRNA and protein expression of pro-IL-1β, cleaved-IL-1β and NLRP3. In addition, the protein levels of TLR4, p-P65 and p-IκB, as well as the translocation of P65 to nucleus, were significantly increased in LPS-induced SiHa cells and Caski cells. LPS stimulation did not change t-P65 and t-IκB on protein levels, which were components of TLR-NF-κB pathway. CD200Fc down-regulated protein expression of TLR4, p-P65 and p-IκB and inhibited the translocation of P65 to nucleus in LPS-induced SiHa cells and Caski cells. These results indicated that CD200Fc appeared to suppress the inflammatory activity of TLR4-NF-κB and NLRP3 inflammasome pathway in LPS-induced SiHa cells and Caski cells. It provided novel mechanistic insights into the potential therapeutic uses of CD200Fc for cervical cancer.

1,25-Dihydroxyvitamin D3 attenuates endotoxin-induced production of inflammatory mediators by inhibiting MAPK activation in primary cortical neuron-glia cultures.

PubMed

Huang, Ya-Ni; Ho, Yi-Jung; Lai, Chien-Cheng; Chiu, Chien-Tsai; Wang, Jia-Yi

2015-08-12

Neuroinflammation occurs in insulted regions of the brain and may be due to reactive oxygen species (ROS), nitric oxide (NO), cytokines, and chemokines produced by activated glia. Excessive production of neurotoxic molecules causes further neuronal damage. Low levels of vitamin D3 are a risk factor for various brain diseases. Using the bacterial endotoxin, lipopolysaccharide (LPS), to induce neuroinflammation in primary cortical neuron-glia cultures, we investigated how 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) affected neuroinflammation. LPS (100 ng/ml) induced the accumulation of nitrite and the production of ROS, interleukin (IL)-6, and macrophage inflammatory protein (MIP)-2 in time-dependent manners. Inhibition of p38 and extracellular signal-regulated kinase (ERK) but not c-Jun N-terminal kinase (JNK) mitogen-activated protein kinase (MAPK) by 20 μM of SB203580, PD98059, and SP600125, significantly reduced LPS-induced ROS production, NO accumulation, and inducible NO synthase (iNOS) expression, respectively. LPS-induced IL-6 and MIP-2 were significantly attenuated by inhibition of p38, ERK, and JNK MAPK. Cotreatment with 1,25(OH)2D3 attenuated LPS-induced ROS production, NO accumulation, and iNOS expression in concentration-dependent manners. 1,25(OH)2D3 also reduced LPS-induced production of IL-6 and MIP-2. Similarly, iNOS, IL-6, and MIP-2 mRNA expression in cells treated with LPS significantly increased, whereas this effect was attenuated by 1,25(OH)2D3. Moreover, LPS-induced phosphorylation of p38, ERK, and JNK MAPK was significantly inhibited by 1,25(OH)2D3. Our findings indicate that 1,25(OH)2D3 reduced the LPS-stimulated production of inflammatory molecules in neuron-glia cultures by inhibiting MAPK pathways and the production of downstream inflammatory molecules. We suggest that 1,25(OH)2D3 can be used to alleviate neuroinflammation in various brain injuries.

Herbal medicine IMOD suppresses LPS-induced production of proinflammatory cytokines in human dendritic cells

PubMed Central

Mirzaee, Saeedeh; Drewniak, Agata; Sarrami-Forooshani, Ramin; Kaptein, Tanja M.; Gharibdoost, Farhad; Geijtenbeek, Teunis B. H.

2015-01-01

Traditional medicines that stimulate or modulate the immune system can be used as innovative approaches to treat immunological diseases. The herbal medicine IMOD has been shown to strongly modulate immune responses in several animal studies as well as in clinical trials. However, little is known about the mechanisms of IMOD to modulate immunity. Here we have investigated whether IMOD modulates the immunological function of human dendritic cells (DCs). IMOD alone did not induce DC maturation nor production of cytokines. Notably, IMOD decreased the production of pro-inflammatory cytokines IL-6, IL-12 p70, and TNFα by LPS-activated DCs at both mRNA and protein levels in a dose dependent manner. In contrast, treatment with IMOD did not affect LPS induced-production of the anti-inflammatory cytokine IL-10. Furthermore, IMOD inhibited T cell activation/proliferation by LPS-treated DCs and skewed T-cells responses toward the T helper type 2 polarization. These data strongly indicate that IMOD has a potent immunomodulatory ability that affects TLR signaling and thereby modulates DC function. Insight into the immunomodulatory effect of herbal medicine IMOD may provide innovative strategies to affect the immune system and to help combat various diseases. PMID:25870561

Protective effects of sea buckthorn polysaccharide extracts against LPS/d-GalN-induced acute liver failure in mice via suppressing TLR4-NF-κB signaling.

PubMed

Liu, Huan; Zhang, Wei; Dong, Shichao; Song, Liang; Zhao, Shimin; Wu, Chunyan; Wang, Xue; Liu, Fang; Xie, Jiming; Wang, Jinling; Wang, Yuzhen

2015-12-24

Sea buckthorn (Hippophae rhamnoides L.) berries have been traditionally used to treat gastric disorders, cardiovascular problems, and liver injuries in oriental medicinal system. This study aimed to explore the protective effects and mechanisms of the polysaccharide extracts of Sea buckthorn (HRP) berries against lipopolysaccharide (LPS) and d-galactosamine hydrochloride (d-GalN)-induced acute liver failure in mice. HRP was isolated by hot-water extraction and characterized by HPLC and infrared spectrum analysis. The total carbohydrate, uronic acid and protein contents of HRP were measured by a spectrophotometric method. Mice were orally administrated with HRP (50, 100, 200mg/kg) once daily for 14 consecutive days prior to the challenge with LPS (50 μg/kg) and d-GalN (300 mg/kg). Animals of positive control group were intraperitoneally injected with dexamethasone (10mg/kg). Mice were sacrificed at 8h after LPS/d-GalN injection. Pretreatment with HRP significantly inhibited LPS/d-GalN-induced increases in serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels, which were accompanied by alleviated liver injuries and reduced production of tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β). HRP was also found to reduce malondialdehyde (MDA) content and to restore superoxide dismutase (SOD) and glutathione peroxidase (GSH-PX) activities. Furthermore, HRP supplementation dose-dependently inhibited the expression of Toll-like receptor 4 (TLR4), phosphorylated extracellular signal-regulated kinase (p-ERK), phosphorylated c-Jun N-terminal kinase (p-JNK), and phosphorylated mitogen activated protein kinase 38 (p-p38 MAPK) in the liver of LPS/d-GalN challenged mice. Pretreatment with HRP also inhibited LPS/d-GalN-induced activation and translocation of nuclear factor-κB (NF-κB). This study indicates that pretreatment with HRP protects against LPS/d-GalN-induced liver injury in mice via suppressing the TLR4-NF-κB signaling pathway. Sea

Monophosphoryl lipid A induces protection against LPS in medullary thick ascending limb through a TLR4-TRIF-PI3K signaling pathway.

PubMed

Watts, Bruns A; George, Thampi; Sherwood, Edward R; Good, David W

2017-07-01

Monophosphoryl lipid A (MPLA) is a detoxified derivative of LPS that induces tolerance to LPS and augments host resistance to bacterial infections. Previously, we demonstrated that LPS inhibits [Formula: see text] absorption in the medullary thick ascending limb (MTAL) through a basolateral Toll-like receptor 4 (TLR4)-myeloid differentiation factor 88 (MyD88)-ERK pathway. Here we examined whether pretreatment with MPLA would attenuate LPS inhibition. MTALs from rats were perfused in vitro with MPLA (1 µg/ml) in bath and lumen or bath alone for 2 h, and then LPS was added to (and MPLA removed from) the bath solution. Pretreatment with MPLA eliminated LPS-induced inhibition of [Formula: see text] absorption. In MTALs pretreated with MPLA plus a phosphatidylinositol 3-kinase (PI3K) or Akt inhibitor, LPS decreased [Formula: see text] absorption. MPLA increased Akt phosphorylation in dissected MTALs. The Akt activation was eliminated by a PI3K inhibitor and in MTALs from TLR4 -/- or Toll/IL-1 receptor domain-containing adaptor-inducing IFN-β (TRIF) -/- mice. The effect of MPLA to prevent LPS inhibition of [Formula: see text] absorption also was TRIF dependent. Pretreatment with MPLA prevented LPS-induced ERK activation; this effect was dependent on PI3K. MPLA alone had no effect on [Formula: see text] absorption, and MPLA pretreatment did not prevent ERK-mediated inhibition of [Formula: see text] absorption by aldosterone, consistent with MPLA's low toxicity profile. These results demonstrate that pretreatment with MPLA prevents the effect of LPS to inhibit [Formula: see text] absorption in the MTAL. This protective effect is mediated directly through MPLA stimulation of a TLR4-TRIF-PI3K-Akt pathway that prevents LPS-induced ERK activation. These studies identify detoxified TLR4-based immunomodulators as novel potential therapeutic agents to prevent or treat renal tubule dysfunction in response to bacterial infections. Copyright © 2017 the American Physiological

Long-term nicotine exposure dampens LPS-induced nerve-mediated airway hyperreactivity in murine airways.

PubMed

Xu, Yuan; Cardell, Lars-Olaf

2017-09-01

Nicotine is a major component of cigarette smoke. It causes addiction and is used clinically to aid smoke cessation. The aim of the present study is to investigate the effect of nicotine on lipopolysaccharide (LPS)-induced airway hyperreactivity (AHR) and to explore the potential involvement of neuronal mechanisms behind nicotine's effects in murine models in vivo and in vitro. BALB/c mice were exposed to nicotine in vivo via subcutaneous Alzet osmotic minipumps containing nicotine tartate salt solution (24 mg·kg -1 ·day -1 ) for 28 days. LPS (0.1 mg/ml, 20 µl) was administered intranasally for 3 consecutive days during the end of this period. Lung functions were measured with flexiVent. For the in vitro experiments, mice tracheae were organcultured with either nicotine (10 μM) or vehicle (DMSO, 0.1%) for 4 days. Contractile responses of the tracheal segments were measured in myographs following electric field stimulation (EFS; increasing frequencies of 0.2 to 12.8 Hz) before and after incubation with 10 µg/ml LPS for 1 h. Results showed that LPS induced AHR to methacholine in vivo and increased contractile responses to EFS in vitro. Interestingly, long-term nicotine exposure markedly dampened this LPS-induced AHR both in vitro and in vivo. Tetrodotoxin (TTX) inhibited LPS-induced AHR but did not further inhibit nicotine-suppressed AHR in vivo. In conclusion, long-term nicotine exposure dampened LPS-induced AHR. The effect of nicotine was mimicked by TTX, suggesting the involvement of neuronal mechanisms. This information might be used for evaluating the long-term effects of nicotine and further exploring of how tobacco products interact with bacterial airway infections. Copyright © 2017 the American Physiological Society.

L-Ascorbate Attenuates the Endotoxin-Induced Production of Inflammatory Mediators by Inhibiting MAPK Activation and NF-κB Translocation in Cortical Neurons/Glia Cocultures

PubMed Central

Huang, Ya-Ni; Lai, Chien-Cheng; Chiu, Chien-Tsai; Lin, Jhen-Jhe; Wang, Jia-Yi

2014-01-01

In response to acute insults to the central nervous system, such as pathogen invasion or neuronal injuries, glial cells become activated and secrete inflammatory mediators such as nitric oxide (NO), cytokines, and chemokines. This neuroinflammation plays a crucial role in the pathophysiology of chronic neurodegenerative diseases. Endogenous ascorbate levels are significantly decreased among patients with septic encephalopathy. Using the bacterial endotoxin lipopolysaccharide (LPS) to induce neuroinflammation in primary neuron/glia cocultures, we investigated how L-ascorbate (vitamin C; Vit. C) affected neuroinflammation. LPS (100 ng/ml) induced the expression of inducible NO synthase (iNOS) and the production of NO, interleukin (IL)-6, and macrophage inflammatory protein-2 (MIP-2/CXCL2) in a time-dependent manner; however, cotreatment with Vit. C (5 or 10 mM) attenuated the LPS-induced iNOS expression and production of NO, IL-6, and MIP-2 production. The morphological features revealed after immunocytochemical staining confirmed that Vit. C suppressed LPS-induced astrocytic and microglial activation. Because Vit. C can be transported into neurons and glia via the sodium-dependent Vit. C transporter-2, we examined how Vit. C affected LPS-activated intracellular signaling in neuron/glia cocultures. The results indicated the increased activation (caused by phosphorylation) of mitogen-activated protein kinases (MAPKs), such as p38 at 30 min and extracellular signal-regulated kinases (ERKs) at 180 min after LPS treatment. The inhibition of p38 and ERK MAPK suppressed the LPS-induced production of inflammatory mediators. Vit. C also inhibited the LPS-induced activation of p38 and ERK. Combined treatments of Vit. C and the inhibitors of p38 and ERK yielded no additional inhibition compared with using the inhibitors alone, suggesting that Vit. C functions through the same signaling pathway (i.e., MAPK) as these inhibitors. Vit. C also reduced LPS-induced Iκ

MiR-103 alleviates autophagy and apoptosis by regulating SOX2 in LPS-injured PC12 cells and SCI rats.

PubMed

Li, Guowei; Chen, Tao; Zhu, Yingxian; Xiao, Xiaoyu; Bu, Juyuan; Huang, Zongwen

2018-03-01

Recent studies revealed that microRNAs (miRNAs) may play crucial roles in the responses and pathologic processes of spinal cord injury (SCI). This study aimed to investigate the effect and the molecular basis of miR-103 on LPS-induced injuries in PC12 cells in vitro and SCI rats in vivo . PC12 cells were exposed to LPS to induce cell injuries to mimic the in vitro model of SCI. The expression of miR-103 and SOX2 in PC12 cells were altered by transient transfections. Cell viability and apoptotic cell rate were measured by CCK-8 assay and flow cytometry assay. Furthermore, Western blot analysis was performed to detect the expression levels of apoptosis- and autophagy- related proteins, MAPK/ERK pathway- and JAK/STAT pathway-related proteins. In addition, we also assessed the effect of miR-103 agomir on SCI rats. LPS exposure induced cell injuries in PC12 cells. miR-103 overexpression significantly increased cell viability, reduced cell apoptosis and autophagy, and opposite results were observed in miR-103 inhibition. miR-103 attenuated LPS-induced injuries by indirect upregulation of SOX2. SOX2 overexpression protected PC12 cells against LPS-induced injuries, while SOX2 inhibition expedited LPS-induced cell injuries. Furthermore, miR-103 overexpression inhibited MAPK/ERK pathway and JAK/STAT pathway through upregulation of SOX2. We also found that miR-103 agomir inhibited cell apoptosis and autophagy in SCI rats. This study demonstrates that miR-103 may represent a protective effect against cell apoptosis and autophagy in LPS-injured PC12 cells and SCI rats by upregulation of SOX2 expression.

Hemin induction of HO-1 protects against LPS-induced septic ileus.

PubMed

Bortscher, Stephan; Chang, Johannes; Vilz, Tim O; Schäfer, Nico; Sommer, Nils; Wehner, Sven; Kalff, Jörg C; Overhaus, Marcus

2012-12-01

Heme oxygenase (HO-1) protects against inflammation. In this study, we investigated the protective function of hemin-induced HO-1 against lipopolysaccharide (LPS)-induced ileus. Rats received LPS intraperitoneally 24 h after intraperitoneal hemin pretreatment or placebo. We also injected zinc protoporphyrin (ZnPP, 3rd group), an inhibitor of HO-1, intraperitoneally 2 h before LPS administration. To assess intestinal muscle function, we examined muscularis strip contractility in an organ bath and measured gastrointestinal transit in vivo. We investigated inflammation within the muscularis using polymerase chain reaction (interleukin [IL]-6, inducible nitric oxide synthase (iNOS), HO-1 and IL-10) 6 and 24 h after LPS. Hemin significantly improved in vitro intestinal muscularis contractility (P < 0.001). In addition, hemin prevented LPS-induced dysmotility in vivo (gastrointestinal transit, geometric center: 8.39 ± 0.33 versus 5.68 ± 0.44; P < 0.001). In Zinc protoporphyrin (ZnPP)-treated animals, both parameters were significantly decreased compared with the hemin group. Messenger RNA expression demonstrated a significant reduction in IL-6 (6 h, hemin: 127.6 ± 36.7 versus LPS: 14,431 ± 5407; 24 h: 1.58 ± 0.39 versus 11.15 ± 2.59; P < 0.01) and iNOS (6 h: 2516 ± 985 versus 50,771 ± 13,321; 24 h: 55.11 ± 10.55 versus 257.1 ± 43.18; P < 0.001) in hemin-treated animals. Anti-inflammatory HO-1 messenger RNA levels (6 h, hemin: 116.3 ± 18.55 versus LPS: 26.02 ± 3.64; 24 h: 18.46 ± 2.69 versus 2.80 ± 0.32; P < 0.001) were increased. There was no significant difference in IL-10 levels at 6 and 24 h. ZnPP reversed the anti-inflammatory hemin effects. Hemin induction of HO-1 diminishes LPS-induced sepsis. Heme oxygenase-1 has a central role in preventing sepsis-induced ileus. This benefit is reversed by HO-1 inhibition with ZnPP. Copyright © 2012 Elsevier Inc. All rights reserved.

Flavonoid Fraction of Bergamot Juice Reduces LPS-Induced Inflammatory Response through SIRT1-Mediated NF-κB Inhibition in THP-1 Monocytes

PubMed Central

Risitano, Roberto; Currò, Monica; Cirmi, Santa; Ferlazzo, Nadia; Campiglia, Pietro; Caccamo, Daniela; Ientile, Riccardo; Navarra, Michele

2014-01-01

Plant polyphenols exert anti-inflammatory activity through both anti-oxidant effects and modulation of pivotal pro-inflammatory genes. Recently, Citrus bergamia has been studied as a natural source of bioactive molecules with antioxidant activity, but few studies have focused on molecular mechanisms underlying their potential beneficial effects. Several findings have suggested that polyphenols could influence cellular function by acting as activators of SIRT1, a nuclear histone deacetylase, involved in the inhibition of NF-κB signaling. On the basis of these observations we studied the anti-inflammatory effects produced by the flavonoid fraction of the bergamot juice (BJe) in a model of LPS-stimulated THP-1 cell line, focusing on SIRT1-mediated NF-κB inhibition. We demonstrated that BJe inhibited both gene expression and secretion of LPS-induced pro-inflammatory cytokines (IL-6, IL-1β, TNF-α) by a mechanism involving the inhibition of NF-κB activation. In addition, we showed that BJe treatment reversed the LPS-enhanced acetylation of p65 in THP-1 cells. Interestingly, increasing concentrations of Sirtinol were able to suppress the inhibitory effect of BJe via p65 acetylation, underscoring that NF-κB–mediated inflammatory cytokine production may be directly linked to SIRT1 activity. These results suggest that BJe may be useful for the development of alternative pharmacological strategies aimed at reducing the inflammatory process. PMID:25260046

Flavonoid fraction of Bergamot juice reduces LPS-induced inflammatory response through SIRT1-mediated NF-κB inhibition in THP-1 monocytes.

PubMed

Risitano, Roberto; Currò, Monica; Cirmi, Santa; Ferlazzo, Nadia; Campiglia, Pietro; Caccamo, Daniela; Ientile, Riccardo; Navarra, Michele

2014-01-01

Plant polyphenols exert anti-inflammatory activity through both anti-oxidant effects and modulation of pivotal pro-inflammatory genes. Recently, Citrus bergamia has been studied as a natural source of bioactive molecules with antioxidant activity, but few studies have focused on molecular mechanisms underlying their potential beneficial effects. Several findings have suggested that polyphenols could influence cellular function by acting as activators of SIRT1, a nuclear histone deacetylase, involved in the inhibition of NF-κB signaling. On the basis of these observations we studied the anti-inflammatory effects produced by the flavonoid fraction of the bergamot juice (BJe) in a model of LPS-stimulated THP-1 cell line, focusing on SIRT1-mediated NF-κB inhibition. We demonstrated that BJe inhibited both gene expression and secretion of LPS-induced pro-inflammatory cytokines (IL-6, IL-1β, TNF-α) by a mechanism involving the inhibition of NF-κB activation. In addition, we showed that BJe treatment reversed the LPS-enhanced acetylation of p65 in THP-1 cells. Interestingly, increasing concentrations of Sirtinol were able to suppress the inhibitory effect of BJe via p65 acetylation, underscoring that NF-κB-mediated inflammatory cytokine production may be directly linked to SIRT1 activity. These results suggest that BJe may be useful for the development of alternative pharmacological strategies aimed at reducing the inflammatory process.

Ursodeoxycholic acid inhibits TNFα-induced IL-8 release from monocytes.

PubMed

O'Dwyer, Aoife M; Lajczak, Natalia K; Keyes, Jennifer A; Ward, Joseph B; Greene, Catherine M; Keely, Stephen J

2016-08-01

Monocytes are critical to the pathogenesis of inflammatory bowel disease (IBD) as they infiltrate the mucosa and release cytokines that drive the inflammatory response. Ursodeoxycholic acid (UDCA), a naturally occurring bile acid with anti-inflammatory actions, has been proposed as a potential new therapy for IBD. However, its effects on monocyte function are not yet known. Primary monocytes from healthy volunteers or cultured U937 monocytes were treated with either the proinflammatory cytokine, TNFα (5 ng/ml) or the bacterial endotoxin, lipopolysaccharide (LPS; 1 μg/ml) for 24 h, in the absence or presence of UDCA (25-100 μM). IL-8 release into the supernatant was measured by ELISA. mRNA levels were quantified by qPCR and changes in cell signaling proteins were determined by Western blotting. Toxicity was assessed by measuring lactate dehydrogenase (LDH) release. UDCA treatment significantly attenuated TNFα-, but not LPS-driven, release of IL-8 from both primary and cultured monocytes. UDCA inhibition of TNFα-driven responses was associated with reduced IL-8 mRNA expression. Both TNFα and LPS stimulated NFκB activation in monocytes, while IL-8 release in response to both cytokines was attenuated by an NFκB inhibitor, BMS-345541. Interestingly, UDCA inhibited TNFα-, but not LPS-stimulated, NFκB activation. Finally, TNFα, but not LPS, induced phosphorylation of TNF receptor associated factor (TRAF2), while UDCA cotreatment attenuated this response. We conclude that UDCA specifically inhibits TNFα-induced IL-8 release from monocytes by inhibiting TRAF2 activation. Since such actions would serve to dampen mucosal immune responses in vivo, our data support the therapeutic potential of UDCA for IBD. Copyright © 2016 the American Physiological Society.

Edaravone protects endotoxin-induced liver injury by inhibiting apoptosis and reducing proinflammatory cytokines.

PubMed

Zong, L; Yu, Q H; Du, Y X; Deng, X M

2014-02-01

Studies have shown that edaravone may prevent liver injury. This study aimed to investigate the effects of edaravone on the liver injury induced by D-galactosamine (GalN) and lipopolysaccharide (LPS) in female BALB/c mice. Edaravone was injected into mice 30 min before and 4 h after GalN/LPS injection. The survival rate was determined within the first 24 h. Animals were killed 8 h after GalN/LPS injection, and liver injury was biochemically and histologically assessed. Hepatocyte apoptosis was measured by TUNEL staining; proinflammatory cytokines [tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6)] in the liver were assayed by ELISA; expression of caspase-8 and caspase-3 proteins was detected by Western blot assay; and caspase-3 activity was also determined. Results showed that GalN/LPS induced marked elevations in serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT). Edaravone significantly inhibited elevation of serum AST and ALT, accompanied by an improvement in histological findings. Edaravone lowered the levels of TNF-α and IL-6 and reduced the number of TUNEL-positive cells. In addition, 24 h after edaravone treatment, caspase-3 activity and mortality were reduced. Edaravone may effectively ameliorate GalN/LPS-induced liver injury in mice by reducing proinflammatory cytokines and inhibiting apoptosis.

Edaravone protects endotoxin-induced liver injury by inhibiting apoptosis and reducing proinflammatory cytokines

PubMed Central

Zong, L.; Yu, Q.H.; Du, Y.X.; Deng, X.M.

2014-01-01

Studies have shown that edaravone may prevent liver injury. This study aimed to investigate the effects of edaravone on the liver injury induced by D-galactosamine (GalN) and lipopolysaccharide (LPS) in female BALB/c mice. Edaravone was injected into mice 30 min before and 4 h after GalN/LPS injection. The survival rate was determined within the first 24 h. Animals were killed 8 h after GalN/LPS injection, and liver injury was biochemically and histologically assessed. Hepatocyte apoptosis was measured by TUNEL staining; proinflammatory cytokines [tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6)] in the liver were assayed by ELISA; expression of caspase-8 and caspase-3 proteins was detected by Western blot assay; and caspase-3 activity was also determined. Results showed that GalN/LPS induced marked elevations in serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT). Edaravone significantly inhibited elevation of serum AST and ALT, accompanied by an improvement in histological findings. Edaravone lowered the levels of TNF-α and IL-6 and reduced the number of TUNEL-positive cells. In addition, 24 h after edaravone treatment, caspase-3 activity and mortality were reduced. Edaravone may effectively ameliorate GalN/LPS-induced liver injury in mice by reducing proinflammatory cytokines and inhibiting apoptosis. PMID:24554039

Gigantol isolated from the whole plants of Cymbidium goeringii inhibits the LPS-induced iNOS and COX-2 expression via NF-kappaB inactivation in RAW 264.7 macrophages cells.

PubMed

Won, Jong-Heon; Kim, Ji-Yeon; Yun, Kyung-Jin; Lee, Jin-Hee; Back, Nam-In; Chung, Hae-Gon; Chung, Sun A; Jeong, Tae-Sook; Choi, Myung-Sook; Lee, Kyung-Tae

2006-10-01

During our efforts to find bioactive natural products with anti-inflammatory activity, we isolated gigantol from the whole plants of Cymbidium goeringii (Orchidaceae) by activity-guided chromatographic fractionation. Gigantol was found to have potent inhibitory effects on LPS-induced nitric oxide (NO) and prostaglandin E (2) (PGE (2)) production in RAW 264.7 cells. Consistent with these findings, gigantol suppressed the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) at the protein and mRNA levels in RAW 264.7 cells in a concentration-dependent manner. Our data also indicate that gigantol is a potent inhibitor of tumor necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta) and interleukin-6 (IL-6) release and influenced the mRNA expression levels of these cytokines in a dose-dependent manner. Furthermore, a reporter gene assay for nuclear factor kappa B (NF-kappaB) and an electromobility shift assay (EMSA) demonstrated that gigantol effectively inhibited the activation of NF-kappaB, which is necessary for the expression of iNOS, COX-2, TNF-alpha, IL-1beta and IL-6. Thus, our studies suggest that gigantol inhibits LPS-induced iNOS and COX-2 expression by blocking NF- kappaB activation.

Low-dose lipopolysaccharide (LPS) inhibits aggressive and augments depressive behaviours in a chronic mild stress model in mice.

PubMed

Couch, Yvonne; Trofimov, Alexander; Markova, Natalyia; Nikolenko, Vladimir; Steinbusch, Harry W; Chekhonin, Vladimir; Schroeter, Careen; Lesch, Klaus-Peter; Anthony, Daniel C; Strekalova, Tatyana

2016-05-16

Aggression, hyperactivity, impulsivity, helplessness and anhedonia are all signs of depressive-like disorders in humans and are often reported to be present in animal models of depression induced by stress or by inflammatory challenges. However, chronic mild stress (CMS) and clinically silent inflammation, during the recovery period after an infection, for example, are often coincident, but comparison of the behavioural and molecular changes that underpin CMS vs a mild inflammatory challenge and impact of the combined challenge is largely unexplored. Here, we examined whether stress-induced behavioural and molecular responses are analogous to lipopolysaccharide (LPS)-induced behavioural and molecular effects and whether their combination is adaptive or maladaptive. Changes in measures of hedonic sensitivity, helplessness, aggression, impulsivity and CNS and systemic cytokine and 5-HT-system-related gene expression were investigated in C57BL/6J male mice exposed to chronic stress alone, low-dose LPS alone or a combination of LPS and stress. When combined with a low dose of LPS, chronic stress resulted in an enhanced depressive-like phenotype but significantly reduced manifestations of aggression and hyperactivity. At the molecular level, LPS was a strong inducer of TNFα, IL-1β and region-specific 5-HT2A mRNA expression in the brain. There was also increased serum corticosterone as well as increased TNFα expression in the liver. Stress did not induce comparable levels of cytokine expression to an LPS challenge, but the combination of stress with LPS reduced the stress-induced changes in 5-HT genes and the LPS-induced elevated IL-1β levels. It is evident that when administered independently, both stress and LPS challenges induced distinct molecular and behavioural changes. However, at a time when LPS alone does not induce any overt behavioural changes per se, the combination with stress exacerbates depressive and inhibits aggressive behaviours.

HSP-70 mitigates LPS/SKI-induced cell damage by increasing sphingosine kinase 1 (SK1).

PubMed

Ding, Xuan Z; Feng, Xiao R; Borschel, Richard H; Nikolich, Mikeljon P; Feng, Jie; Li, Yan S; Hoover, David L

2010-06-01

Heat shock proteins (HSPs) are potent protectors of cellular integrity against environmental stresses, including toxic microbial products. To investigate the mechanism of HSP-70 cell protection against bacterial lipopolysaccharide (LPS), we established a stable HSP-70 gene-transfected RAW 264.7 murine macrophage model of LPS-induced cell death. Bacterial LPS increases the activity of sphingosine kinase 1 (SK1), which catalyzes formation of sphingosine-1-phosphate (S1P). S1P functions as a critical signal for initiation and maintenance of diverse aspects of immune cell activation and function. When mouse macrophages were incubated with Escherichia coli LPS (1 microg/ml) and sphingosine kinase inhibitor (SKI, 5 microM), 90% of cells died. Neither LPS nor SKI alone at these doses damaged the cells. The LPS/SKI-induced cell death was partially reversed by overexpression of HSP-70 in gene-transfected macrophages. The specificity of HSP-70 in this reversal was demonstrated by transfection of HSP-70-specific siRNA. Down-regulation of HSP-70 expression after transfection of siRNA specific for HSP-70 was associated with increased LPS/SKI-induced cell damage. Overexpression of human or murine HSP-70 (HSPA1A and Hspa1a, respectively) increased both cellular SK1 mRNA and protein levels. Cellular heat shock also increased SK1 protein. These studies confirm the importance of SK1 as a protective moiety in LPS-induced cell injury and demonstrate that HSP-70-mediated protection from cells treated with LPS/SKI is accompanied by upregulating expression of SK1. HSP-70-mediated increases in SK1 and consequent increased levels of S1P may also play a role in protection of cells from other processes that lead to programmed cell death. Published by Elsevier Inc.

Lipopolysaccharide (LPS)-stimulated iNOS Induction Is Increased by Glucosamine under Normal Glucose Conditions but Is Inhibited by Glucosamine under High Glucose Conditions in Macrophage Cells*

PubMed Central

Hwang, Ji-Sun; Kwon, Mi-Youn; Kim, Kyung-Hong; Lee, Yunkyoung; Lyoo, In Kyoon; Kim, Jieun E.; Oh, Eok-Soo; Han, Inn-Oc

2017-01-01

We investigated the regulatory effect of glucosamine (GlcN) for the production of nitric oxide (NO) and expression of inducible NO synthase (iNOS) under various glucose conditions in macrophage cells. At normal glucose concentrations, GlcN dose dependently increased LPS-stimulated production of NO/iNOS. However, GlcN suppressed NO/iNOS production under high glucose culture conditions. Moreover, GlcN suppressed LPS-induced up-regulation of COX-2, IL-6, and TNF-α mRNAs under 25 mm glucose conditions yet did not inhibit up-regulation under 5 mm glucose conditions. Glucose itself dose dependently increased LPS-induced iNOS expression. LPS-induced MAPK and IκB-α phosphorylation did not significantly differ at normal and high glucose conditions. The activity of LPS-induced nuclear factor-κB (NF-κB) and DNA binding of c-Rel to the iNOS promoter were inhibited under high glucose conditions in comparison with no significant changes under normal glucose conditions. In addition, we found that the LPS-induced increase in O-GlcNAcylation as well as DNA binding of c-Rel to the iNOS promoter were further increased by GlcN under normal glucose conditions. However, both O-GlcNAcylation and DNA binding of c-Rel decreased under high glucose conditions. The NF-κB inhibitor, pyrrolidine dithiocarbamate, inhibited LPS-induced iNOS expression under high glucose conditions but it did not influence iNOS induction under normal glucose conditions. In addition, pyrrolidine dithiocarbamate inhibited NF-κB DNA binding and c-Rel O-GlcNAcylation only under high glucose conditions. By blocking transcription with actinomycin D, we found that stability of LPS-induced iNOS mRNA was increased by GlcN under normal glucose conditions. These results suggest that GlcN regulates inflammation by sensing energy states of normal and fuel excess. PMID:27927986

Citral inhibits lipopolysaccharide-induced acute lung injury by activating PPAR-γ.

PubMed

Shen, Yongbin; Sun, Zhanfeng; Guo, Xiaotong

2015-01-15

Citral, a component of lemongrass oil, has been reported to have many pharmacological activities such as anti-bacterial and anti-inflammatory effects. However, the effects of citral on acute lung injury (ALI) and the molecular mechanisms have not been reported. The aim of this study was to detect the effects of citral on lipopolysaccharide (LPS)-induced acute lung injury and investigate the molecular mechanisms. LPS-induced acute lung injury model was used to detect the anti-inflammatory effect of citral in vivo. The alveolar macrophages were used to investigate the molecular mechanism of citral in vitro. The results showed that pretreatment with citral remarkably attenuated pulmonary edema, histological severities, TNF-α, IL-6 and IL-1β production in LPS-induced ALI in vivo. In vitro, citral inhibited LPS-induced TNF-α, IL-6 and IL-1β production in alveolar macrophages. LPS-induced NF-κB activation was also inhibited by citral. Furthermore, we found that citral activated PPAR-γ and the anti-inflammatory effects of citral can be reversed by PPAR-γ antagonist GW9662. In conclusion, this is the first to demonstrate that citral protects LPS-induced ALI in mice. The anti-inflammatory mechanism of citral is associated with activating PPAR-γ, thereby inhibiting LPS-induced inflammatory response. Copyright © 2014 Elsevier B.V. All rights reserved.

Decoy peptide targeted to Toll-IL-1R domain inhibits LPS and TLR4-active metabolite morphine-3 glucuronide sensitization of sensory neurons.

PubMed

Allette, Yohance M; Kim, Youngsook; Randolph, Aaron L; Smith, Jared A; Ripsch, Matthew S; White, Fletcher A

2017-06-16

Accumulating evidence indicates that Toll-like receptor (TLR) signaling adapter protein interactions with Toll/Interleukin-1 Receptor (TIR) domains present in sensory neurons may modulate neuropathic pain states. Following ligand interaction with TLRs, TIR serves to both initiate intracellular signaling and facilitate recruitment of signaling adapter proteins to the intracytoplasmic domain. Although TLR TIR is central to a number of TLR signaling cascades, its role in sensory neurons is poorly understood. In this study we investigated the degree to which TLR TIR decoy peptide modified to include a TAT sequence (Trans-Activator of Transcription gene in HIV; TAT-4BB) affected LPS-induced intracellular calcium flux and excitation in sensory neurons, and behavioral changes due to TLR4 active metabolite, morphine-3-glucuronide (M3G) exposure in vivo. TAT-4BB inhibited LPS-induced calcium changes in a majority of sensory neurons and decreased LPS-dependent neuronal excitability in small diameter neurons. Acute systemic administration of the TAT-4BB reversed M3G-induced tactile allodynia in a dose-dependent manner but did not affect motor activity, anxiety or responses to noxious thermal stimulus. These data suggest that targeting TLR TIR domains may provide novel pharmacological targets to reduce or reverse TLR4-dependent pain behavior in the rodent.

A rhodium(III) complex inhibits LPS-induced nitric oxide production and angiogenic activity in cellulo.

PubMed

Liu, Li-Juan; Lin, Sheng; Chan, Daniel Shiu-Hin; Vong, Chi Teng; Hoi, Pui Man; Wong, Chun-Yuen; Ma, Dik-Lung; Leung, Chung-Hang

2014-11-01

Metal-containing complexes have arisen as viable alternatives to organic molecules as therapeutic agents. Metal complexes possess a number of advantages compared to conventional carbon-based compounds, such as distinct geometries, interesting electronic properties, variable oxidation states and the ability to arrange different ligands around the metal centre in a precise fashion. Meanwhile, nitric oxide (NO) plays key roles in the regulation of angiogenesis, vascular permeability and inflammation. We herein report a novel cyclometalated rhodium(III) complex as an inhibitor of lipopolysaccharides (LPS)-induced NO production in RAW264.7 macrophages. Experiments suggested that the inhibition of NO production in cells by complex 1 was mediated through the down-regulation of nuclear factor-κB (NF-κB) activity. Furthermore, complex 1 inhibited angiogenesis in human umbilical vein endothelial cells (HUVECs) as revealed by an endothelial tube formation assay. This study demonstrates that kinetically inert rhodium(III) complexes may be potentially developed as effective anti-angiogenic agents. Copyright © 2014 Elsevier Inc. All rights reserved.

Kyungheechunggan-Tang-01, a New Herbal Medication, Suppresses LPS-Induced Inflammatory Responses through JAK/STAT Signaling Pathway in RAW 264.7 Macrophages

PubMed Central

Han, Hee-Soo; Shin, Ji-Sun; Inn, Kyung-Soo; Lee, Jang-Hoon; Park, Geonha

2017-01-01

Medicinal plants have been used as alternative therapeutic tools to alleviate inflammatory diseases. The objective of this study was to evaluate anti-inflammatory properties of Kyungheechunggan-tang- (KCT-) 01, KCT-02, and Injinchunggan-tang (IJCGT) as newly developed decoctions containing 3–11 herbs in LPS-induced macrophages. KCT-01 showed the most potent inhibitory effects on LPS-induced NO, PGE2, TNF-α, and IL-6 production among those three herbal formulas. In addition, KCT-01 significantly inhibited LPS-induced iNOS and COX-2 at protein levels and expression of iNOS, COX-2, TNF-α, and IL-6 at mRNA levels. Molecular data revealed that KCT-01 attenuated the activation of JAK/STAT signaling cascade without affecting NF-κB or AP-1 activation. In ear inflammation induced by croton oil, KCT-01 significantly reduced edema, MPO activity, expression levels of iNOS and COX-2, and STAT3 phosphorylation in ear tissues. Taken together, our findings suggest that KCT-01 can downregulate the expression of proinflammatory genes by inhibiting JAK/STAT signaling pathway under inflammatory conditions. This study provides useful data for further exploration and application of KCT-01 as a potential anti-inflammatory medicine. PMID:29348772

An apple oligogalactan suppresses endotoxin-induced cyclooxygenase-2 expression by inhibition of LPS pathways.

PubMed

Li, Yuhua; Fan, Lei; Sun, Yang; Zhang, Dian; Yue, Zhenggang; Niu, Yinbo; Meng, Jin; Yang, Tiehong; Liu, Wenchao; Mei, Qibing

2013-10-01

Colorectal cancer (CRC) is one of the most common cancers and a leading cause of cancer-related mortality in developed countries. Many ingredients of apples have been proven to have anti-inflammatory and anti-carcinogenic characteristics, and show benefits for CRC prevention. The aim of this study, therefore, was to evaluate inhibitory effect of an apple oligogalactan (AOG) on pro-inflammatory endotoxin lipopolysaccharide (LPS)-activated human colon carcinoma cells HT-29 and SW-620 and investigate the possible mechanisms. The two cell lines were pretreated with AOG (0.1-1 g/L) for 30 min and then treated with 10 μg/mL LPS. Real time PCR, Western blot, electrophoretic mobility shift assay (EMSA), and ELISA were used to detect the expression and activity of cyclooxygenase-2 (COX-2), NF-κB and MAPKs pathways. AOG significantly inhibited the expression and activity of COX-2 in LPS-activated human colon carcinoma cells HT-29 and SW-620. The mechanisms of AOG-suppressed COX-2 expression may be through inhibiting the phosphorylation of MAPKs and the activation of NF-κB and AP-1. These data may provide another molecular basis for understanding how apples act to prevent CRC and indicate that AOG may be useful for treatment of colitis and prevention of carcinogenesis. Copyright © 2013 Elsevier B.V. All rights reserved.

LPS inhibits caspase 3-dependent apoptosis in RAW264.7 macrophages induced by the AMPK activator AICAR

DOE Office of Scientific and Technical Information (OSTI.GOV)

Russe, Otto Quintus, E-mail: quintus@russe.eu; Möser, Christine V., E-mail: chmoeser@hotmail.com; Kynast, Katharina L., E-mail: katharina.kynast@googlemail.com

2014-05-09

Highlights: • AMPK-activation induces caspase 3-dependent apoptosis in macrophages. • Apoptosis is associated with decreased mTOR and increased p21 levels. • All effects can be significantly inhibited by the TLR4 agonist lipopolysaccharide. - Abstract: AMP-activated kinase is a cellular energy sensor which is activated in stages of increased ATP consumption. Its activation has been associated with a number of beneficial effects such as decreasing inflammatory processes and the disease progress of diabetes and obesity, respectively. Furthermore, AMPK activation has been linked with induction of cell cycle arrest and apoptosis in cancer and vascular cells, indicating that it might have amore » therapeutic impact for the treatment of cancer and atherosclerosis. However, the impact of AMPK on the proliferation of macrophages, which also play a key role in the formation of atherosclerotic plaques and in inflammatory processes, has not been focused so far. We have assessed the influence of AICAR- and metformin-induced AMPK activation on cell viability of macrophages with and without inflammatory stimulation, respectively. In cells without inflammatory stimulation, we found a strong induction of caspase 3-dependent apoptosis associated with decreased mTOR levels and increased expression of p21. Interestingly, these effects could be inhibited by co-stimulation with bacterial lipopolysaccharide (LPS) but not by other proinflammatory cytokines suggesting that AICAR induces apoptosis via AMPK in a TLR4-pathway dependent manner. In conclusion, our results revealed that AMPK activation is not only associated with positive effects but might also contribute to risk factors by disturbing important features of macrophages. The fact that LPS is able to restore AMPK-associated apoptosis might indicate an important role of TLR4 agonists in preventing unfavorable cell death of immune cells.« less

Apigenin inhibits d-galactosamine/LPS-induced liver injury through upregulation of hepatic Nrf-2 and PPARγ expressions in mice.

PubMed

Zhou, Rui-Jun; Ye, Hua; Wang, Feng; Wang, Jun-Long; Xie, Mei-Lin

2017-11-04

Apigenin is a natural flavonoid compound widely distributed in a variety of vegetables, medicinal plants and health foods. This study aimed to examine the protective effect of apigenin against d-galactosamine (D-GalN)/lipopolysaccharide (LPS)-induced mouse liver injury and to investigate the potential biochemical mechanisms. The results showed that after oral administration of apigenin 100-200 mg/kg for 7 days, the levels of serum alanine aminotransferase and aspartate aminotransferase were decreased, and the severity of liver injury was alleviated. Importantly, apigenin pretreatment increased the levels of hepatic nuclear factor erythroid 2-related factor 2 (Nrf-2) and peroxisome proliferator-activated receptor γ (PPARγ) protein expressions as well as superoxide dismutase, catalase, glutathione S-transferase and glutathione reductase activities, decreased the levels of hepatic nuclear factor-κB (NF-κB) protein expression and tumor necrosis factor-α. These findings demonstrated that apigenin could prevent the D-GalN/LPS-induced liver injury in mice, and its mechanisms might be associated with the increments of Nrf-2-mediated antioxidative enzymes and modulation of PPARγ/NF-κB-mediated inflammation. Copyright © 2017 Elsevier Inc. All rights reserved.

MicroRNA-211/BDNF axis regulates LPS-induced proliferation of normal human astrocyte through PI3K/AKT pathway

PubMed Central

Zhang, Kexiang; Wu, Song; Li, Zhiyue

2017-01-01

Spinal cord injury (SCI) makes a major contribution to disability and deaths worldwide. Reactive astrogliosis, a typical feature after SCI, which undergoes varying molecular and morphological changes, is ubiquitous but poorly understood. Reactive astrogliosis contributes to glial scar formation that impedes axonal regeneration. Brain-derived neurotrophic factor (BDNF), a well-established neurotrophic factor, exerts neuroprotective and growth-promoting effects on a variety of neuronal populations after injury. In the present study, by using LPS-induced in vitro injury model of astroglial cultures, we observed a high expression of interleukin (IL)-6, IL-1β, and BDNF in LPS-stimulated normal human astrocytes (NHAs). BDNF significantly promoted NHA proliferation. Further, online tools were employed to screen the candidate miRNAs which might directly target BDNF to inhibit its expression. Amongst the candidate miRNAs, miR-211 expression was down-regulated by LPS stimulation in a dose-dependent manner. Through direct targetting, miR-211 inhibited BDNF expression. Ectopic miR-211 expression significantly suppressed NHA proliferation, as well as LPS-induced activation of PI3K/Akt pathway. In contrast, inhibition of miR-211 expression significantly promoted NHA proliferation and LPS-induced activation of PI3K/Akt pathway. Taken together, miR-211/BDNF axis regulates LPS-induced NHA proliferation through PI3K/AKT pathway; miR-211/BDNF might serve as a promising target in the strategy against reactive astrocyte proliferation after SCI. PMID:28790168

Flavonoid Apigenin Inhibits Lipopolysaccharide-Induced Inflammatory Response through Multiple Mechanisms in Macrophages

PubMed Central

Zhang, Xiaoxuan; Wang, Guangji; Gurley, Emily C.; Zhou, Huiping

2014-01-01

Background Apigenin is a non-toxic natural flavonoid that is abundantly present in common fruits and vegetables. It has been reported that apigenin has various beneficial health effects such as anti-inflammation and chemoprevention. Multiple studies have shown that inflammation is an important risk factor for atherosclerosis, diabetes, sepsis, various liver diseases, and other metabolic diseases. Although it has been long realized that apigenin has anti-inflammatory activities, the underlying functional mechanisms are still not fully understood. Methodology and Principal Findings In the present study, we examined the effect of apigenin on LPS-induced inflammatory response and further elucidated the potential underlying mechanisms in human THP-1-induced macrophages and mouse J774A.1 macrophages. By using the PrimePCR array, we were able to identify the major target genes regulated by apigenin in LPS-mediated immune response. The results indicated that apigenin significantly inhibited LPS-induced production of pro-inflammatory cytokines, such as IL-6, IL-1β, and TNF-α through modulating multiple intracellular signaling pathways in macrophages. Apigenin inhibited LPS-induced IL-1β production by inhibiting caspase-1 activation through the disruption of the NLRP3 inflammasome assembly. Apigenin also prevented LPS-induced IL-6 and IL-1β production by reducing the mRNA stability via inhibiting ERK1/2 activation. In addition, apigenin significantly inhibited TNF-α and IL-1β-induced activation of NF-κB. Conclusion and Significance Apigenin Inhibits LPS-induced Inflammatory Response through multiple mechanisms in macrophages. These results provided important scientific evidences for the potential application of apigenin as a therapeutic agent for inflammatory diseases. PMID:25192391

Withaferin A down-regulates lipopolysaccharide-induced cyclooxygenase-2 expression and PGE2 production through the inhibition of STAT1/3 activation in microglial cells.

PubMed

Min, Kyoung-Jin; Choi, Kyounghwa; Kwon, Taeg Kyu

2011-08-01

Microglia are the major immune effector cells in the brain, and microglia activated by injury and infection can produce inflammatory mediators. A number of studies have reported that withaferin A has anti-inflammatory functions. However, the effects of withaferin A on the microglial inflammatory response have not been investigated. Our results show that withaferin A inhibited lipopolysaccharide (LPS)-induced cyclooxygenase (COX)-2 mRNA and protein expression and prostaglandin E2 (PGE(2)) production in BV2 murine microglial cells. Withaferin A had no effect on LPS-induced Akt and ERK phosphorylation, but phosphorylation of p38 and JNK was slightly decreased by withaferin A. Withaferin A significantly inhibited LPS-induced STAT1 and STAT3 phosphorylation in a dose-dependent manner. Furthermore, withaferin A inhibited nuclear translocation of STAT1 and interferon-gamma activated sequence (GAS)-promoter activity. Taken together, these results suggest that withaferin A inhibits LPS-induced PGE(2) production and COX-2 expression, at least in part, by blocking STAT1 and STAT3 activation. Copyright © 2011 Elsevier B.V. All rights reserved.

Differential regulation of CD44 expression by lipopolysaccharide (LPS) and TNF-alpha in human monocytic cells: distinct involvement of c-Jun N-terminal kinase in LPS-induced CD44 expression.

PubMed

Gee, Katrina; Lim, Wilfred; Ma, Wei; Nandan, Devki; Diaz-Mitoma, Francisco; Kozlowski, Maya; Kumar, Ashok

2002-11-15

Alterations in the regulation of CD44 expression play a critical role in modulating cell adhesion, migration, and inflammation. LPS, a bacterial cell wall component, regulates CD44 expression and may modulate CD44-mediated biological effects in monocytic cells during inflammation and immune responses. In this study, we show that in normal human monocytes, LPS and LPS-induced cytokines IL-10 and TNF-alpha enhance CD44 expression. To delineate the mechanism underlying LPS-induced CD44 expression, we investigated the role of the mitogen-activated protein kinases (MAPKs), p38, p42/44 extracellular signal-regulated kinase, and c-Jun N-terminal kinase (JNK) by using their specific inhibitors. We demonstrate the involvement, at least in part, of p38 MAPK in TNF-alpha-induced CD44 expression in both monocytes and promonocytic THP-1 cells. However, neither p38 nor p42/44 MAPKs were involved in IL-10-induced CD44 expression in monocytes. To further dissect the TNF-alpha and LPS-induced signaling pathways regulating CD44 expression independent of IL-10-mediated effects, we used IL-10 refractory THP-1 cells as a model system. Herein, we show that CD44 expression induced by the LPS-mediated pathway predominantly involved JNK activation. This conclusion was based on results derived by transfection of THP-1 cells with a dominant-negative mutant of stress-activated protein/extracellular signal-regulated kinase kinase 1, and by exposure of cells to JNK inhibitors dexamethasone and SP600125. All these treatments prevented CD44 induction in LPS-stimulated, but not in TNF-alpha-stimulated, THP-1 cells. Furthermore, we show that CD44 induction may involve JNK-dependent early growth response gene activation in LPS-stimulated monocytic cells. Taken together, these results suggest a predominant role of JNK in LPS-induced CD44 expression in monocytic cells.

Endogenous pleiotrophin and midkine regulate LPS-induced glial responses.

PubMed

Fernández-Calle, Rosalía; Vicente-Rodríguez, Marta; Gramage, Esther; de la Torre-Ortiz, Carlos; Pérez-García, Carmen; Ramos, María P; Herradón, Gonzalo

2018-01-01

Pleiotrophin (PTN) and Midkine (MK) are two growth factors that modulate neuroinflammation. PTN overexpression in the brain prevents LPS-induced astrocytosis in mice but potentiates microglial activation. The modest astrocytic response caused by a low dose of LPS (0.5mg/kg) is blocked in the striatum of MK-/- mice whereas microglial response is unaffected. We have now tested the effects of an intermediate dose of LPS (7.5mg/kg) in glial response in PTN-/- and MK-/- mice. We found that LPS-induced astrocytosis is prevented in prefrontal cortex and striatum of both PTN-/- and MK-/- mice. Some of the morphological changes of microglia induced by LPS tended to increase in both genotypes, particularly in PTN-/- mice. Since we previously showed that PTN potentiates LPS-induced activation of BV2 microglial cells, we tested the activation of FYN kinase, a substrate of the PTN receptor RPTPβ/ζ, and the subsequent ERK1/2 phosphorylation on LPS and PTN-treated BV2 cells. LPS effects on BV2 cells were not affected by the addition of PTN, suggesting that PTN does not recruit the FYN-MAP kinase signaling pathway in order to modulate LPS effects on microglial cells. Taking together, evidences demonstrate that regulation of astroglial responses to LPS administration are highly dependent on the levels of expression of PTN and MK. Further studies are needed to clarify the possible roles of endogenous expression of PTN and MK in LPS-induced microglial responses. Copyright © 2017 Elsevier B.V. All rights reserved.

Bergenin Plays an Anti-Inflammatory Role via the Modulation of MAPK and NF-κB Signaling Pathways in a Mouse Model of LPS-Induced Mastitis.

PubMed

Gao, Xue-jiao; Guo, Meng-yao; Zhang, Ze-cai; Wang, Tian-cheng; Cao, Yong-guo; Zhang, Nai-sheng

2015-01-01

Mastitis is a major disease in humans and other animals and is characterized by mammary gland inflammation. It is a major disease of the dairy industry. Bergenin is an active constituent of the plants of genus Bergenia. Research indicates that bergenin has multiple biological activities, including anti-inflammatory and immunomodulatory properties. The objective of this study was to evaluate the protective effects and mechanism of bergenin on the mammary glands during lipopolysaccharide (LPS)-induced mastitis. In this study, mice were treated with LPS to induce mammary gland mastitis as a model for the disease. Bergenin treatment was initiated after LPS stimulation for 24 h. The results indicated that bergenin attenuated inflammatory cell infiltration and decreased the concentration of NO, TNF-α, IL-1β, and IL-6, which were increased in LPS-induced mouse mastitis. Furthermore, bergenin downregulated the phosphorylation of nuclear factor-kappaB (NF-κB) and mitogen-activated protein kinases (MAPK) signaling pathway proteins in mammary glands with mastitis. In conclusion, bergenin reduced the expression of NO, TNF-α, IL-1β, and IL-6 proinflammatory cytokines by inhibiting the activation of the NF-κB and MAPKs signaling pathways, and it may represent a novel treatment strategy for mastitis.

Neuroprotective effects of pretreatment with propofol in LPS-induced BV-2 microglia cells: role of TLR4 and GSK-3β.

PubMed

Gui, Bo; Su, Mingyan; Chen, Jie; Jin, Lai; Wan, Rong; Qian, Yanning

2012-10-01

Surgery often leads to neuroinflammation, which mainly acts as the activation of microglia cells. Propofol is always used for induction and maintenance of anesthesia prior to surgical trauma, whereas whether or not it could attenuate neuroinflammation used prophylactically is not well defined. In the present study, we incubated BV-2 microglia cells with 1 μg/ml lipopolysaccharide (LPS) to mimic neuroinflammation in vitro. Firstly, cell viability was measured using 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay and the data indicated that propofol would not reduce cell viability unless its concentration reached 300 μM. Secondly, BV-2 microglia cells were pretreated with 30 μM propofol (clinically relevant concentration), and then stimulated with LPS. The results showed that the production of tumor necrosis factor-α (TNF-α), interleukin (IL)-1β and IL-10 was considerably increased by LPS, but the change could be markedly attenuated by pretreatment with propofol. Meanwhile, pretreatment with propofol inhibited LPS-induced augmentation of toll-like receptor 4 (TLR4) expression at both mRNA and protein levels and further upregulated LPS-induced inactivation of glycogen synthase kinase-3β (GSK-3β) in BV-2 microglia cells. These results indicated, at least in part, that pretreatment with propofol can protect BV-2 microglia cells against LPS-induced inflammation. Downregulation of TLR4 expression and inactivation of GSK-3β may be involved in its protective effect.

Oleoylethanolamide exerts anti-inflammatory effects on LPS-induced THP-1 cells by enhancing PPARα signaling and inhibiting the NF-κB and ERK1/2/AP-1/STAT3 pathways.

PubMed

Yang, Lichao; Guo, Han; Li, Ying; Meng, Xianglan; Yan, Lu; Dan Zhang; Wu, Sangang; Zhou, Hao; Peng, Lu; Xie, Qiang; Jin, Xin

2016-10-10

The present study aimed to examine the anti-inflammatory actions of oleoylethanolamide (OEA) in lipopolysaccharide (LPS)-induced THP-1 cells. The cells were stimulated with LPS (1 μg/ml) in the presence or absence of OEA (10, 20 and 40 μM). The pro-inflammatory cytokines were evaluated by qRT-PCR and ELISA. The THP-1 cells were transiently transfected with PPARα small-interfering RNA, and TLR4 activity was determined with a blocking test using anti-TLR4 antibody. Additionally, a special inhibitor was used to analyse the intracellular signaling pathway. OEA exerted a potent anti-inflammatory effect by reducing the production of pro-inflammatory cytokines and TLR4 expression, and by enhancing PPARα expression. The modulatory effects of OEA on LPS-induced inflammation depended on PPARα and TLR4. Importantly, OEA inhibited LPS-induced NF-κB activation, IκBα degradation, expression of AP-1, and the phosphorylation of ERK1/2 and STAT3. In summary, our results demonstrated that OEA exerts anti-inflammatory effects by enhancing PPARα signaling, inhibiting the TLR4-mediated NF-κB signaling pathway, and interfering with the ERK1/2-dependent signaling cascade (TLR4/ERK1/2/AP-1/STAT3), which suggests that OEA may be a therapeutic agent for inflammatory diseases.

Protein-bound polysaccharides from Coriolus versicolor attenuate LPS-induced synthesis of pro-inflammatory cytokines and stimulate PBMCs proliferation.

PubMed

Jędrzejewski, Tomasz; Pawlikowska, Małgorzata; Piotrowski, Jakub; Kozak, Wiesław

2016-10-01

Protein-bound polysaccharides (PBP) isolated from Coriolus versicolor (CV) are classified as biological response modifiers capable of exhibiting various biological activities, such as anti-tumour and immunopotentiating activity. Since we have found in vivo studies that the tested PBP induced prolongation of endotoxin fever in rats, the aim of the present study was to investigate the in vitro effect of the PBP on the production of pro-inflammatory cytokines by the lipolysaccharide (LPS)-stimulated rat peripheral blood mononuclear cells (PBMCs). The results showed that the PBP affect the immunomodulating properties of the LPS-treated PBMCs by the enhancement of mitogenic activity and attenuation of the LPS-induced production of interleukin (IL)-1β and IL-6. Moreover, the tested polysaccharides peptides themselves also exhibit immunomodulatory properties manifested in the increased cell proliferation and pro-inflammatory cytokine release from PBMCs. The effect of PBP on the both phenomena was time-dependent and occurred in the U-shaped dose response manner. These findings are significant when considering the use of commercially available PBP from CV extract by cancer patients suffering from immunodeficiency, who may experience microbial infections during therapy. Copyright © 2016 European Federation of Immunological Societies. Published by Elsevier B.V. All rights reserved.

Cyanidin-3-glucoside inhibits inflammatory activities in human fibroblast-like synoviocytes and in mice with collagen-induced arthritis.

PubMed

Sun, Yan; Li, Lingling

2018-05-19

Rheumatoid arthritis (RA) is a chronic autoimmune disease characterized by joint tissue inflammation. Cyanidin-3-glucoside (C3G) is a major component in the flavonoid family and has shown anti-inflammatory, anti-oxidant and anti-tumor activity. In this study, we investigated the effects of C3G on lipopolysaccharides (LPS)-induced inflammation on human rheumatoid fibroblast-like synoviocytes (FLS) and on collagen-induced arthritis (CIA) mice model. We treated FLS with C3G followed by LPS induction, the expressions of tumor necrosis factor alpha (TNF-α), interleukin 1 beta (IL-1β) and IL-6 and the activation of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathway were analyzed. CIA was induced in mice and the arthritic mice were treated with C3G for 3 weeks. The disease severity was compared between control and C3G treated mice. The serum levels of TNF-α, IL-1β and IL-6 were analyzed by ELISA. C3G inhibited LPS-induced TNF-α, IL-1β and IL-6 expression in FLS. Moreover, C3G inhibited LPS-induced p65 production and IκBa, p38, ERK and JNK phosphorylation. Administration of C3G significantly attenuated disease in mice with CIA and decreased the serum level of TNF-α, IL-1β and IL-6. C3G inhibited LPS-induced inflammation in human FLS by inhibiting activation of NF-κB and MAPK signaling pathway. C3G exhibited therapeutic effects in mice with CIA. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Protective effects of aerobic exercise on acute lung injury induced by LPS in mice

PubMed Central

2012-01-01

Introduction The regular practice of physical exercise has been associated with beneficial effects on various pulmonary conditions. We investigated the mechanisms involved in the protective effect of exercise in a model of lipopolysaccharide (LPS)-induced acute lung injury (ALI). Methods Mice were divided into four groups: Control (CTR), Exercise (Exe), LPS, and Exercise + LPS (Exe + LPS). Exercised mice were trained using low intensity daily exercise for five weeks. LPS and Exe + LPS mice received 200 µg of LPS intratracheally 48 hours after the last physical test. We measured exhaled nitric oxide (eNO); respiratory mechanics; neutrophil density in lung tissue; protein leakage; bronchoalveolar lavage fluid (BALF) cell counts; cytokine levels in BALF, plasma and lung tissue; antioxidant activity in lung tissue; and tissue expression of glucocorticoid receptors (Gre). Results LPS instillation resulted in increased eNO, neutrophils in BALF and tissue, pulmonary resistance and elastance, protein leakage, TNF-alpha in lung tissue, plasma levels of IL-6 and IL-10, and IL-1beta, IL-6 and KC levels in BALF compared to CTR (P ≤0.02). Aerobic exercise resulted in decreases in eNO levels, neutrophil density and TNF-alpha expression in lung tissue, pulmonary resistance and elastance, and increased the levels of IL-6, IL-10, superoxide dismutase (SOD-2) and Gre in lung tissue and IL-1beta in BALF compared to the LPS group (P ≤0.04). Conclusions Aerobic exercise plays important roles in protecting the lungs from the inflammatory effects of LPS-induced ALI. The effects of exercise are mainly mediated by the expression of anti-inflammatory cytokines and antioxidants, suggesting that exercise can modulate the inflammatory-anti-inflammatory and the oxidative-antioxidative balance in the early phase of ALI. PMID:23078757

Effect of curcumin (Curcuma longa extract) on LPS-induced acute lung injury is mediated by the activation of AMPK.

PubMed

Kim, Joungmin; Jeong, Seong-Wook; Quan, Hui; Jeong, Cheol-Won; Choi, Jeong-Il; Bae, Hong-Beom

2016-02-01

Curcumin, a biphenolic compound extracted from turmeric (Curcuma longa), possesses potent anti-inflammatory activity. The present study investigated whether curcumin could increase 5' adenosine monophosphate-activated protein kinase (AMPK) activity in macrophages and modulate the severity of lipopolysaccharide (LPS)-induced acute lung injury. Macrophages were treated with curcumin and then exposed (or not) to LPS. Acute lung injury was induced by intratracheal administration of LPS in BALB/c mice. Curcumin increased phosphorylation of AMPK and acetyl-CoA carboxylase (ACC), a downstream target of AMPK, in a time- and concentration-dependent manner. Curcumin did not increase phosphorylation of liver kinase B1, a primary kinase upstream of AMPK. STO-609, an inhibitor of calcium(2+)/calmodulin-dependent protein kinase kinase, diminished curcumin-induced AMPK phosphorylation, but transforming growth factor-beta-activated kinase 1 inhibitor did not. Curcumin also diminished the LPS-induced increase in phosphorylation of inhibitory κB-alpha and the production of tumor necrosis factor alpha (TNF-α), macrophage inflammatory protein (MIP)-2, and interleukin (IL)-6 by macrophages. Systemic administration of curcumin significantly decreased the production of TNF-α, MIP-2, and IL-6 as well as neutrophil accumulation in bronchoalveolar lavage fluid, and also decreased pulmonary myeloperoxidase levels and the wet/dry weight ratio in mice subjected to LPS treatment. These results suggest that the protective effect of curcumin on LPS-induced acute lung injury is associated with AMPK activation.

Paeonol attenuates acute lung injury by inhibiting HMGB1 in lipopolysaccharide-induced shock rats.

PubMed

Liu, Xia; Xu, Qin; Mei, Liyan; Lei, Hang; Wen, Quan; Miao, Jifei; Huang, Huina; Chen, Dongfeng; Du, Shaohui; Zhang, Saixia; Zhou, Jianhong; Deng, Rudong; Li, Yiwei; Li, Chun; Li, Hui

2018-06-05

High-mobility group box 1 (HMGB1) is a highly conserved DNA-binding nuclear protein that facilitates gene transcription and the DNA repair response. However, HMGB1 may be released by necrotic cells as well as activated monocytes and macrophages following stimulation with lipopolysaccharide (LPS), interleukin-1β (IL-1β), or tumor necrosis factor-α (TNF-α). Extracellular HMGB1 plays a critical role in the pathogenesis of acute lung injury (ALI) through activating the nuclear transcription factor κB (NF-κB) P65 pathway, thus, it may be a promising therapeutic target in shock-induced ALI. Paeonol (Pae) is the main active component of Paeonia suffruticosa, which has been used to inhibit the inflammatory response in traditional Chinese medicine. We have proven that Pae inhibits the expression, relocation and secretion of HMGB1 in vitro. However, the role of Pae in the HMGB1-NF-κB pathway remains unknown. We herein investigated the role of Pae in LPS-induced ALI rats. In this study, LPS induced a marked decrease in the mean arterial pressure (MAP) and survival rate (only 25% after 72 h), and induced severe pathological changes in the lung tissue of rats, which was accompanied by elevated expression of HMGB1 and its downstream protein NF-κB P65. Treatment with Pae significantly improved the survival rate (>60%) and MAP, and attenuated the pathological damage to the lung tissue in ALI rats. Western blotting revealed that Pae also inhibited the total expression of HMGB1, NF-κB P65 and TNF-α in the lung tissue of ALI rats. Moreover, Pae increased the expression of HMGB1 in the nucleus, inhibited the production of HMGB1 in the cytoplasm, and decreased the expression of P65 both in the nucleus and cytoplasm of lung tissue cells in LPS-induced ALI rats. The results were in agreement with those observed in the in vitro experiment. These findings indicate that Pae may be a potential treatment for ALI through its repression of the HMGB1-NF-κB P65 signaling pathway

Baicalein attenuates inflammatory responses by suppressing TLR4 mediated NF-κB and MAPK signaling pathways in LPS-induced mastitis in mice.

PubMed

He, Xuexiu; Wei, Zhengkai; Zhou, Ershun; Chen, Libin; Kou, Jinhua; Wang, Jingjing; Yang, Zhengtao

2015-09-01

Baicalein is a phenolic flavonoid presented in the dry roots of Scutellaria baicalensis Georgi. It has been reported that baicalein possesses a number of biological properties, such as antiviral, antioxidative, anti-inflammatory, antithrombotic, and anticancer properties. However, the effect of baicalein on mastitis has not yet been reported. This research aims to detect the effect of baicalein on lipopolysaccharide (LPS)-induced mastitis in mice and to investigate the molecular mechanisms. Baicalein was administered intraperitoneally 1h before and 12h after LPS treatment. The results indicated that baicalein treatment markedly attenuated the damage of the mammary gland induced by LPS, suppressed the activity of myeloperoxidase (MPO) and the levels of tumor necrosis factor (TNF-α) and interleukin (IL-1β) in mice with LPS-induced mastitis. Besides, baicalein blocked the expression of Toll-like receptor 4 (TLR4) and then suppressed the phosphorylation of nuclear transcription factor-kappaB (NF-κB) p65 and degradation inhibitor of NF-κBα (IκBα) and, and inhibited the phosphorylation of p38, extracellular signal-regulated kinase (ERK) and c-jun NH2-terminal kinase (JNK) in mitogen-activated protein kinase (MAPK) signal pathway. These findings suggested that baicalein may have a potential prospect against mastitis. Copyright © 2015. Published by Elsevier B.V.

Adiponectin attenuates LPS-induced acute lung injury through suppression of endothelial cell activation1

PubMed Central

Konter, Jason M; Parker, Jennifer L; Baez, Elizabeth; Li, Stephanie Z; Ranscht, Barbara; Denzel, Martin; Little, Frederic F; Nakamura, Kazuto; Ouchi, Noriyuki; Fine, Alan; Walsh, Kenneth; Summer, Ross S

2011-01-01

Adiponectin (APN) is an adipose tissue-derived factor with anti-inflammatory and vascular protective properties whose levels paradoxically decrease with increasing body fat. In this study, APN’s role in the early development of ALI to lipopolysaccharide (LPS) was investigated. Intra-tracheal (i.t.) LPS elicited an exaggerated systemic inflammatory response in APN-deficient (APN−/−) mice compared to wild-type (wt) littermates. Increased lung injury and inflammation were observed in APN−/− mice as early as 4 hours after delivery of LPS. Targeted gene expression profiling performed on immune and endothelial cells isolated from lung digests 4 hours after LPS administration showed increased pro-inflammatory gene expression (e.g. IL-6) only in endothelial cells of APN−/− mice when compared to wt mice. Direct effects on lung endothelium were demonstrated by APN’s ability to inhibit LPS-induced IL-6 production in primary human endothelial cells in culture. Furthermore, T-cadherin-deficient (T-cad−/−) mice that have significantly reduced lung airspace APN but high serum APN levels had pulmonary inflammatory responses after i.t. LPS that were similar to those of wt mice. These findings indicate the importance of serum APN in modulating LPS-induced ALI and suggest that conditions leading to hypoadiponectinemia (e.g. obesity) predispose to development of ALI through exaggerated inflammatory response in pulmonary vascular endothelium. PMID:22156343

FLICE-like inhibitory protein (FLIP) protects against apoptosis and suppresses NF-kappaB activation induced by bacterial lipopolysaccharide.

PubMed

Bannerman, Douglas D; Eiting, Kristine T; Winn, Robert K; Harlan, John M

2004-10-01

Bacterial lipopolysaccharide (LPS) via its activation of Toll-like receptor-4 contributes to much of the vascular injury/dysfunction associated with gram-negative sepsis. Inhibition of de novo gene expression has been shown to sensitize endothelial cells (EC) to LPS-induced apoptosis, the onset of which correlates with decreased expression of FLICE-like inhibitory protein (FLIP). We now have data that conclusively establish a role for FLIP in protecting EC against LPS-induced apoptosis. Overexpression of FLIP protected against LPS-induced apoptosis, whereas down-regulation of FLIP using antisense oligonucleotides sensitized EC to direct LPS killing. Interestingly, FLIP overexpression suppressed NF-kappaB activation induced by LPS, but not by phorbol ester, suggesting a specific role for FLIP in mediating LPS activation. Conversely, mouse embryo fibroblasts (MEF) obtained from FLIP -/- mice showed enhanced LPS-induced NF-kappaB activation relative to those obtained from wild-type mice. Reconstitution of FLIP-/- MEF with full-length FLIP reversed the enhanced NF-kappaB activity elicited by LPS in the FLIP -/- cells. Changes in the expression of FLIP had no demonstrable effect on other known LPS/Tlr-4-activated signaling pathways including the p38, Akt, and Jnk pathways. Together, these data support a dual role for FLIP in mediating LPS-induced apoptosis and NF-kappaB activation.

S632A3, a new glutarimide antibiotic, suppresses lipopolysaccharide-induced pro-inflammatory responses via inhibiting the activation of glycogen synthase kinase 3β.

PubMed

Deng, Hongbin; Zhang, Na; Wang, Yan; Chen, Jinjing; Shen, Jiajia; Wang, Zhen; Xu, Rong; Zhang, Jingpu; Song, Danqing; Li, Diandong

2012-12-10

Inflammatory mediators including inducible nitric oxide (iNOS), cyclooxygenase-2 (COX-2), tumor necrosis factor-α (TNF-α) and Interleukin-6 (IL-6) contribute to the course of a variety of inflammatory diseases. S632A3 is a new member of the glutarimide antibiotics isolated from a cultured broth of Streptomyces hygroscopicus S632 with a potent NF-κB inhibitory activity. In the present study, we investigated the anti-inflammatory effects and the underlying molecular mechanism of S632A3 on lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages. S632A3 concentration-dependently inhibited LPS-induced NO and prostaglandin E(2) (PGE(2)) production through the suppression of iNOS and COX-2 at gene transcription levels. In addition, S632A3 suppressed NF-κB-dependent inflammatory responses by inhibiting the activation of glycogen synthase kinase 3β (GSK-3β), while the activation of IκB kinase (IKK) complex was unaffected. S632A3 suppressed NF-κB activity by differentially affecting the CREB (cAMP response element-binding protein) and NF-κB p65 interacting with the coactivator CBP (CREB binding protein). S632A3 also inhibited GSK-3β-elicited iNOS and COX-2 expression. Moreover, S632A3 was shown to inhibit the activation of ASK1 (Apoptosis-signal regulating kinase 1) and p38 mitogen-activated protein kinase, therefore attenuated the LPS-induced NF-κB activity in macrophages. Furthermore, S632A3 significantly reduced the pro-inflammatory cytokines TNF-α and IL-6 production while increased the anti-inflammatory cytokine IL-10 production in LPS-stimulated RAW264.7 cells. Our study thus provides a molecular mechanism by which S632A3 inhibited LPS-induced pro-inflammatory response in macrophages through interfering with the activation of GSK-3β and ASK1-p38 signaling. Copyright © 2012 Elsevier Inc. All rights reserved.

Ketamine inhibits tumor necrosis factor-{alpha} and interleukin-6 gene expressions in lipopolysaccharide-stimulated macrophages through suppression of toll-like receptor 4-mediated c-Jun N-terminal kinase phosphorylation and activator protein-1 activation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wu, G.-J.; Department of Anesthesiology, Shin Kong Wu Ho-Su Memorial Hospital, Taipei, Taiwan; Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan

2008-04-01

Our previous study showed that ketamine, an intravenous anesthetic agent, has anti-inflammatory effects. In this study, we further evaluated the effects of ketamine on the regulation of tumor necrosis factor-{alpha} (TNF-{alpha}) and interlukin-6 (IL-6) gene expressions and its possible signal-transducing mechanisms in lipopolysaccharide (LPS)-activated macrophages. Exposure of macrophages to 1, 10, and 100 {mu}M ketamine, 100 ng/ml LPS, or a combination of ketamine and LPS for 1, 6, and 24 h was not cytotoxic to macrophages. A concentration of 1000 {mu}M of ketamine alone or in combined treatment with LPS caused significant cell death. Administration of LPS increased cellular TNF-{alpha}more » and IL-6 protein levels in concentration- and time-dependent manners. Meanwhile, treatment with ketamine concentration- and time-dependently alleviated the enhanced effects. LPS induced TNF-{alpha} and IL-6 mRNA syntheses. Administration of ketamine at a therapeutic concentration (100 {mu}M) significantly inhibited LPS-induced TNF-{alpha} and IL-6 mRNA expressions. Application of toll-like receptor 4 (TLR4) small interfering (si)RNA into macrophages decreased cellular TLR4 levels. Co-treatment of macrophages with ketamine and TLR4 siRNA decreased the LPS-induced TNF-{alpha} and IL-6 productions more than alone administration of TLR4 siRNA. LPS stimulated phosphorylation of c-Jun N-terminal kinase and translocation of c-Jun and c-Fos from the cytoplasm to nuclei. However, administration of ketamine significantly decreased LPS-induced activation of c-Jun N-terminal kinase and translocation of c-Jun and c-Fos. LPS increased the binding of nuclear extracts to activator protein-1 consensus DNA oligonucleotides. Administration of ketamine significantly ameliorated LPS-induced DNA binding activity of activator protein-1. Therefore, a clinically relevant concentration of ketamine can inhibit TNF-{alpha} and IL-6 gene expressions in LPS-activated macrophages. The suppressive

Ketamine inhibits tumor necrosis factor-alpha and interleukin-6 gene expressions in lipopolysaccharide-stimulated macrophages through suppression of toll-like receptor 4-mediated c-Jun N-terminal kinase phosphorylation and activator protein-1 activation.

PubMed

Wu, Gone-Jhe; Chen, Ta-Liang; Ueng, Yune-Fang; Chen, Ruei-Ming

2008-04-01

Our previous study showed that ketamine, an intravenous anesthetic agent, has anti-inflammatory effects. In this study, we further evaluated the effects of ketamine on the regulation of tumor necrosis factor-alpha (TNF-alpha) and interlukin-6 (IL-6) gene expressions and its possible signal-transducing mechanisms in lipopolysaccharide (LPS)-activated macrophages. Exposure of macrophages to 1, 10, and 100 microM ketamine, 100 ng/ml LPS, or a combination of ketamine and LPS for 1, 6, and 24 h was not cytotoxic to macrophages. A concentration of 1000 microM of ketamine alone or in combined treatment with LPS caused significant cell death. Administration of LPS increased cellular TNF-alpha and IL-6 protein levels in concentration- and time-dependent manners. Meanwhile, treatment with ketamine concentration- and time-dependently alleviated the enhanced effects. LPS induced TNF-alpha and IL-6 mRNA syntheses. Administration of ketamine at a therapeutic concentration (100 microM) significantly inhibited LPS-induced TNF-alpha and IL-6 mRNA expressions. Application of toll-like receptor 4 (TLR4) small interfering (si)RNA into macrophages decreased cellular TLR4 levels. Co-treatment of macrophages with ketamine and TLR4 siRNA decreased the LPS-induced TNF-alpha and IL-6 productions more than alone administration of TLR4 siRNA. LPS stimulated phosphorylation of c-Jun N-terminal kinase and translocation of c-Jun and c-Fos from the cytoplasm to nuclei. However, administration of ketamine significantly decreased LPS-induced activation of c-Jun N-terminal kinase and translocation of c-Jun and c-Fos. LPS increased the binding of nuclear extracts to activator protein-1 consensus DNA oligonucleotides. Administration of ketamine significantly ameliorated LPS-induced DNA binding activity of activator protein-1. Therefore, a clinically relevant concentration of ketamine can inhibit TNF-alpha and IL-6 gene expressions in LPS-activated macrophages. The suppressive mechanisms occur through

Dried Ginger (Zingiber officinalis) Inhibits Inflammation in a Lipopolysaccharide-Induced Mouse Model

PubMed Central

Choi, You Yeon; Kim, Mi Hye; Hong, Jongki; Kim, Sung-Hoon

2013-01-01

Objectives. Ginger rhizomes have a long history of human use, especially with regards to their anti-inflammatory properties. However, the mechanisms by which ginger acts on lipopolysaccharide-(LPS-)induced inflammation have not yet been identified. We investigated the anti-inflammatory effects of dried Zingiber officinalis (DZO) on LPS-induced hepatic injury. Methods. ICR mice were given a DZO water extract (100, 1000 mg/kg) orally for three consecutive days. On the third day, they were administered by LPS intraperitoneally. To investigate the anti-inflammatory effects of DZO, histological, cytokine expression, and protein factor analyses were performed. Results. Oral administration of DZO significantly reduced pathological changes in the liver and proinflammatory cytokines including interferon-(IFN-)γ and interleukin-(IL-)6 in the serum. In addition, DZO inhibited LPS-induced NF-κB activation by preventing degradation of the IκB-α, as well as the phosphorylation of ERK1/2, SAPK/JNK, and p38 MAPKs. These were associated with a decrease in the expression of inducible nitric oxide synthase (iNOS) and cyclooxyenase-2 (COX-2). Conclusions. Our data provide evidence for the hepatoprotective mechanisms of DZO as an anti-inflammatory effect. Furthermore, use of DZO to treat could provide therapeutic benefits in clinical settings. PMID:23935687

Deoxyelephantopin ameliorates lipopolysaccharides (LPS)-induced memory impairments in rats: Evidence for its anti-neuroinflammatory properties.

PubMed

Andy, Shathiswaran N; Pandy, Vijayapandi; Alias, Zazali; Kadir, Habsah Abdul

2018-08-01

Neuroinflammation is a critical pathogenic mechanism of most neurodegenerative disorders especially, Alzheimer's disease (AD). Lipopolysaccharides (LPS) are known to induce neuroinflammation which is evident from significant upsurge of pro-inflammatory mediators in in vitro BV-2 microglial cells and in vivo animal models. In present study, we investigated anti-neuroinflammatory properties of deoxyelephantopin (DET) isolated from Elephantopus scaber in LPS-induced neuroinflammatory rat model. In this study, DET (0.625. 1.25 and 2.5 mg/kg, i.p.) was administered in rats for 21 days and those animals were challenged with single injection of LPS (250 μg/kg, i.p.) for 7 days. Cognitive and behavioral assessment was carried out for 7 days followed by molecular assessment on brain hippocampus. Statistical significance was analyzed with one-way analysis of variance followed by Dunnett's test to compare the treatment groups with the control group. DET ameliorated LPS-induced neuroinflammation by suppressing major pro-inflammatory mediators such as iNOS and COX-2. Furthermore, DET enhanced the anti-inflammatory cytokines and concomitantly suppressed the pro-inflammatory cytokines and chemokine production. DET treatment also reversed LPS-induced behavioral and memory deficits and attenuated LPS-induced elevation of the expression of AD markers. DET improved synaptic-functionality via enhancing the activity of pre- and post-synaptic markers, like PSD-95 and SYP. DET also prevented LPS-induced apoptotic neurodegeneration via inhibition of PARP-1, caspase-3 and cleaved caspase-3. Overall, our studies suggest DET can prevent neuroinflammation-associated memory impairment and neurodegeneration and it could be developed as a therapeutic agent for the treatment of neuroinflammation-mediated and neurodegenerative disorders, such as AD. Copyright © 2018 Elsevier Inc. All rights reserved.

ILK mediates LPS-induced vascular adhesion receptor expression and subsequent leucocyte trans-endothelial migration.

PubMed

Hortelano, Sonsoles; López-Fontal, Raquel; Través, Paqui G; Villa, Natividad; Grashoff, Carsten; Boscá, Lisardo; Luque, Alfonso

2010-05-01

The inflammatory response to injurious agents is tightly regulated to avoid adverse consequences of inappropriate leucocyte accumulation or failed resolution. Lipopolysaccharide (LPS)-activated endothelium recruits leucocytes to the inflamed tissue through controlled expression of membrane-associated adhesion molecules. LPS responses in macrophages are known to be regulated by integrin-linked kinase (ILK); in this study, we investigated the role of ILK in the regulation of the LPS-elicited inflammatory response in endothelium. This study was performed on immortalized mouse endothelial cells (EC) isolated from lung and coronary vasculature. Cells were thoroughly characterized and the role of ILK in the regulation of the LPS response was investigated by suppressing ILK expression using siRNA and shRNA technologies. Phenotypic and functional analyses confirmed that the immortalized cells behaved as true EC. LPS induced the expression of the inflammatory genes E-selectin, intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1). ILK knockdown impaired LPS-mediated endothelial activation by preventing the induction of ICAM-1 and VCAM-1. Blockade of the LPS-induced response inhibited the inflammatory-related processes of firm adhesion and trans-endothelial migration of leucocytes. ILK is involved in the expression of cell adhesion molecules by EC activated with the inflammatory stimulus LPS. This reduced expression modulates leucocyte adhesion to the endothelium and the extravasation process. This finding suggests ILK as a potential anti-inflammatory target for the development of vascular-specific treatments for inflammation-related diseases.

TNF-α and LPS activate angiogenesis via VEGF and SIRT1 signalling in human dental pulp cells.

PubMed

Shin, M R; Kang, S K; Kim, Y S; Lee, S Y; Hong, S C; Kim, E-C

2015-07-01

To assess whether SIRT1 and VEGF are responsible for tumour necrosis factor-α (TNF-α) and lipopolysaccharide (LPS)-induced angiogenesis and to examine the molecular mechanism(s) of action in human dental pulp cells (HDPCs). Immortalized HDPCs obtained from Prof. Takashi Takata (Hiroshima University, Japan) were treated with LPS (1 μg mL(-1) ) and TNF-α (10 ng mL(-1) ) for 24 h. mRNA and protein levels were examined by RT-PCR and Western blotting, respectively. Migration and tube formation were examined in human umbilical vein endothelial cells (HUVECs). The data were analysed by one-way anova. Statistical analysis was performed at α = 0.05. LPS and TNF-α upregulated VEGF and SIRT1 mRNA and protein levels. Inhibition of SIRT1 activity by sirtinol and SIRT1 siRNA or inhibition of the VEGF receptor by CBO-P11 significantly attenuated LPS + TNF-α-stimulated MMPs production in HDPCs, as well as migration and tube formation in HUVECs (P < 0.05). Furthermore, sirtinol, SIRT1 siRNA and CBO-P11 attenuated phosphorylation of Akt, extracellular signal-regulated kinase (ERK), p38 and c-Jun N-terminal kinase (JNK) and the nuclear translocation of NF-κB p65. Pre-treatment with inhibitors of p38, ERK, JNK, PI3K and NF-κB decreased LPS + TNF-α-induced VEGF and SIRT1 expression, MMPs activity in HDPCs and angiogenesis (P < 0.05) in HUVECs. TNF-α and LPS led to upregulation of VEGF and SIRT1, and subsequent upregulation of MMP-2 and MMP-9 production, and promote angiogenesis via pathways involving PI3K, p38, ERK, JNK and NF-κB. The results suggest that inhibition of SIRT1 and VEGF might attenuate pro-inflammatory mediator-induced pulpal disease. © 2014 International Endodontic Journal. Published by John Wiley & Sons Ltd.

Induction of Heme Oxygenase-1 by Sodium 9-Hydroxyltanshinone IIA Sulfonate Derivative Contributes to Inhibit LPS-Mediated Inflammatory Response in Macrophages.

PubMed

Liu, Xin-Hua; Wang, Xi-Ling; Xin, Hong; Wu, Dan; Xin, Xiao-Ming; Miao, Lei; Zhang, Qiu-Yan; Zhou, Yang; Liu, Qian; Zhang, Qian; Zhu, Yi-Zhun

2015-01-01

Sodium 9-acetoxyltanshinone IIA sulfonate (ZY-1A4), a novel compound derived from sodium 9-hydroxyltanshinone IIA sulfonate, was synthesized with potential biological activities. This study aimed to explore the effects of ZY-1A4 on lipopolysaccharide (LPS)-triggered inflammatory response and the underlying mechanisms. Activation of RAW264.7 macrophages was induced by LPS. The effects of ZY-1A4 on inducible nitric oxide synthase (iNOS) expression, nitric oxide (NO) generation, nuclear factor-κB (NF-κB) activation, heme oxygenase-1 (HO-1) expression, and nuclear factor-erythroid 2 related factor 2 (Nrf2) pathway were evaluated to elucidate its underlying mechanisms on inflammatory responses. ZY-1A4 concentration-dependently reduced iNOS expression and NO production, and inhibited c-Jun-N-terminal kinase 1/2 (JNK1/2) phosphorylation and NF-κB activation in LPS-stimulated macrophages. In addition, ZY-1A4 concentration- and time-dependently induced HO-1 expression associated with degradation of Kelch-like ECH-associated protein 1 (Keap1) and nuclear translocation of Nrf2, while the effect of ZY-1A4 was abolished by a phosphoinositide 3-kinase (PI3K) inhibitor LY294002. Intriguingly, pharmacological inactivation of HO-1 with zinc protoporphyrin IX reversed anti-inflammatory effect of ZY- 1A4, but the anti-inflammatory effect of ZY-1A4 was largely mimicked by HO-1 by-products carbon monoxide and bilirubin. Furthermore, the inhibitory effect of ZY-1A4 on LPS-induced iNOS expression and NO release was abolished by HO-1 siRNA or LY294002. Our results demonstrated that ZY-1A4 suppressed LPS-induced iNOS expression and NO generation via modulation of NF-κB activation and HO-1 expression. This new finding might shed light to the prevention and therapy of cardiovascular diseases. © 2015 S. Karger AG, Basel.

Pseudane-VII Isolated from Pseudoalteromonas sp. M2 Ameliorates LPS-Induced Inflammatory Response In Vitro and In Vivo

PubMed Central

Kim, Mi Eun; Jung, Inae; Na, Ju Yong; Kim, Woo Jung; Kim, Young-Ok; Park, Yong-Duk; Lee, Jun Sik

2017-01-01

The ocean is a rich resource of flora, fauna, food, and biological products. We found a wild-type bacterial strain, Pseudoalteromonas sp. M2, from marine water and isolated various secondary metabolites. Pseudane-VII is a compound isolated from the Pseudoalteromonas sp. M2 metabolite that possesses anti-melanogenic activity. Inflammation is a response of the innate immune system to microbial infections. Macrophages have a critical role in fighting microbial infections and inflammation. Recent studies reported that various compounds derived from natural products can regulate immune responses including inflammation. However, the anti-inflammatory effects and mechanism of pseudane-VII in macrophages are still unknown. In this study, we investigated the anti-inflammatory effects of pseudane-VII. In present study, lipopolysaccharide (LPS)-induced nitric oxide (NO) production was significantly decreased by pseudane-VII treatment at 6 μM. Moreover, pseudane-VII treatment dose-dependently reduced mRNA levels of pro-inflammatory cytokines including inos, cox-2, il-1β, tnf-α, and il-6 in LPS-stimulated macrophages. Pseudane-VII also diminished iNOS protein levels and IL-1β secretion. In addition, Pseudane-VII elicited anti-inflammatory effects by inhibiting ERK, JNK, p38, and nuclear factor (NF)-κB-p65 phosphorylation. Consistently, pseudane-VII was also shown to inhibit the LPS-stimulated release of IL-1β and expression of iNOS in mice. These results suggest that pseudane-VII exerted anti-inflammatory effects on LPS-stimulated macrophage activation via inhibition of ERK, JNK, p38 MAPK phosphorylation, and pro-inflammatory gene expression. These findings may provide new approaches in the effort to develop anti-inflammatory therapeutics. PMID:29104209

Pseudane-VII Isolated from Pseudoalteromonas sp. M2 Ameliorates LPS-Induced Inflammatory Response In Vitro and In Vivo.

PubMed

Kim, Mi Eun; Jung, Inae; Lee, Jong Suk; Na, Ju Yong; Kim, Woo Jung; Kim, Young-Ok; Park, Yong-Duk; Lee, Jun Sik

2017-11-01

The ocean is a rich resource of flora, fauna, food, and biological products. We found a wild-type bacterial strain, Pseudoalteromonas sp. M2, from marine water and isolated various secondary metabolites. Pseudane-VII is a compound isolated from the Pseudoalteromonas sp. M2 metabolite that possesses anti-melanogenic activity. Inflammation is a response of the innate immune system to microbial infections. Macrophages have a critical role in fighting microbial infections and inflammation. Recent studies reported that various compounds derived from natural products can regulate immune responses including inflammation. However, the anti-inflammatory effects and mechanism of pseudane-VII in macrophages are still unknown. In this study, we investigated the anti-inflammatory effects of pseudane-VII. In present study, lipopolysaccharide (LPS)-induced nitric oxide (NO) production was significantly decreased by pseudane-VII treatment at 6 μM. Moreover, pseudane-VII treatment dose-dependently reduced mRNA levels of pro-inflammatory cytokines including inos , cox-2 , il-1β , tnf-α , and il-6 in LPS-stimulated macrophages. Pseudane-VII also diminished iNOS protein levels and IL-1β secretion. In addition, Pseudane-VII elicited anti-inflammatory effects by inhibiting ERK, JNK, p38, and nuclear factor (NF)-κB-p65 phosphorylation. Consistently, pseudane-VII was also shown to inhibit the LPS-stimulated release of IL-1β and expression of iNOS in mice. These results suggest that pseudane-VII exerted anti-inflammatory effects on LPS-stimulated macrophage activation via inhibition of ERK, JNK, p38 MAPK phosphorylation, and pro-inflammatory gene expression. These findings may provide new approaches in the effort to develop anti-inflammatory therapeutics.

γ-Oryzanol suppresses COX-2 expression by inhibiting reactive oxygen species-mediated Erk1/2 and Egr-1 signaling in LPS-stimulated RAW264.7 macrophages.

PubMed

Shin, Soon Young; Kim, Heon-Woong; Jang, Hwan-Hee; Hwang, Yu-Jin; Choe, Jeong-Sook; Kim, Jung-Bong; Lim, Yoongho; Lee, Young Han

2017-09-16

Cyclooxygenase (COX)-2 produces prostanoids, which contribute to inflammatory responses. Nuclear factor (NF)-κB is a key transcription factor mediating COX-2 expression. γ-Oryzanol is an active component in rice bran oil, which inhibits lipopolysaccharide (LPS)-mediated COX-2 expression by inhibiting NF-κB. However, the inhibition of COX-2 expression by γ-oryzanol independently of NF-κB is poorly understood. We found that LPS upregulated Egr-1 expression at the transcriptional level. Forced expression of Egr-1 trans-activated the Cox-2 promoter independently of NF-κB. In contrast, silencing of Egr-1 abrogated LPS-mediated COX-2 expression. LPS produced reactive oxygen species (ROS), which, in turn, induced Egr-1 expression via the Erk1/2 MAPK pathway. ROS scavenging activity of γ-oryzanol suppressed Egr-1 expression by inhibiting the Erk1/2 MAPK pathway. Our results suggest that γ-oryzanol inhibits LPS-mediated COX-2 expression by suppressing Erk1/2-mediated Egr-1 expression. This study supports that γ-oryzanol may be useful for ameliorating LPS-mediated inflammatory responses. Copyright © 2017 Elsevier Inc. All rights reserved.

Fluocinolone acetonide partially restores the mineralization of LPS-stimulated dental pulp cells through inhibition of NF-κB pathway and activation of AP-1 pathway

PubMed Central

Liu, Zhongning; Jiang, Ting; Wang, Xinzhi; Wang, Yixiang

2013-01-01

BACKGROUND AND PURPOSE Fluocinolone acetonide (FA) is commonly used as a steroidal anti-inflammatory drug. We recently found that in dental pulp cells (DPCs) FA has osteo-/odonto-inductive as well as anti-inflammatory effects. However, the mechanism by which FA induces these effects in DPCs is poorly understood. EXPERIMENTAL APPROACH The effect of FA on the mineralization of DPCs during inflammatory conditions and the underlying mechanism were investigated by real-time PCR, Western blot, EMSA, histochemical staining, immunostaining and pathway blockade assays. KEY RESULTS FA significantly inhibited the inflammatory response in LPS-treated DPCs not only by down-regulating the expression of pro–inflammation-related genes, but also by up-regulating the expression of the anti-inflammatory gene PPAR-γ and mineralization-related genes. Moreover, histochemical staining and immunostaining showed that FA could partially restore the expressions of alkaline phosphatase, osteocalcin and dentin sialophosphoprotein (DSPP) and mineralization in LPS-stimulated DPCs. Real-time PCR and Western blot analysis revealed that FA up-regulated DSPP and runt-related transcription factor 2 expression by inhibiting the expression of phosphorylated-NF-κB P65 and activating activator protein-1 (AP-1) (p-c-Jun and Fra-1). These results were further confirmed through EMSA, by detection of NF-κB DNA-binding activity and pathway blockade assays using a NF-κB pathway inhibitor, AP-1 pathway inhibitor and glucocorticoid receptor antagonist. CONCLUSIONS AND IMPLICATIONS Inflammation induced by LPS suppresses the mineralization process in DPCs. FA partially restored this osteo-/odonto-genesis process in LPS-treated DPCs and had an anti-inflammatory effect through inhibition of the NF-κB pathway and activation of the AP-1 pathway. Hence, FA is a potential new treatment for inflammation-associated bone/teeth diseases. PMID:24024985

Monocyte B7 and Sialyl Lewis X modulates the efficacy of IL-10 down-regulation of LPS-induced monocyte tissue factor in whole blood.

PubMed

Warnes, G; Biggerstaff, J P; Francis, J L

1998-07-01

Recent studies have investigated the use of anti-inflammatory cytokine, interleukin 10 (IL-10) to control the development of disseminated intravascular coagulation (DIC) in sepsis by down-regulation of monocyte tissue factor (MTF) induced by lipopolysaccharide (LPS) in the initial phase of the disease. In vitro and in vivo human studies have shown that a minimal (<1 h) delay in IL-10 treatment significantly reduces the cytokines ability to inhibit LPS-induced MTF expression and the end products of coagulation. In this whole blood in vitro study we investigated the role of lymphocyte and platelet interactions with monocytes to up-regulate MTF expression in the presence of IL-10 in the initial phase of exposure to LPS. Individual blockade of monocyte B7 or platelet P-selectin significantly (35%) reduced MTF expression (P<0.05). IL-10 showed a dose-dependent inhibition of LPS (0.1 microg/ml) induced MTF expression, with 56% inhibition at 1 ng/ml, maximizing at 5 ng/ml IL-10 (75%; P<0.05). Simultaneous exposure to LPS and IL-10 (1 ng/ml) or addition of IL-10 1 h after LPS, with individual B7 and P-selectin blockade significantly enhanced the inhibition of MTF expression by IL-10 (P<0.05). We conclude that the efficacy of IL-10 to control DIC could be enhanced by a simultaneous B7 and P-selectin blockade.

A 5-hydroxyoxindole derivative attenuates LPS-induced inflammatory responses by activating the p38-Nrf2 signaling axis.

PubMed

Niino, Tomomi; Tago, Kenji; Yasuda, Daisuke; Takahashi, Kyoko; Mashino, Tadahiko; Tamura, Hiroomi; Funakoshi-Tago, Megumi

2018-06-22

5-Hydroxyoxindole is a urinary metabolite of indole that exhibits antioxidant activity. In the present study, we found that a 5-hydroxyoxindole derivative (5-HI) significantly inhibited LPS-induced inflammatory effects in the murine macrophage cell line, RAW264.7. 5-HI induced the expression of the transcription factor, Nrf2, which is typically ubiquitinated by Keap1, an adaptor component of the ubiquitin E3 ligase complex, resulting in its proteasomal degradation. By utilizing Keap1-/- MEFs reconstituted with Keap1 mutants harboring substitutions in their major cysteine residues, we clarified the importance of Cys151 in Keap1 as a sensor for 5-HI in the induction of Nrf2 expression. Furthermore, 5-HI induced the activation of the MKK3/6-p38 pathway, which is required for the transcriptional activation of Nrf2. The knockdown of Nrf2 enhanced the LPS-induced expression of inflammatory mediators, including iNOS, NO, and CCL2, and effectively repressed the inhibitory effects of 5-HI on their expression. Although 5-HI and antioxidant N-acetyl cysteine (NAC) both reduced LPS-induced ROS generation, the treatment with NAC did not affect the LPS-induced expression of inflammatory mediators, suggesting that the anti-inflammatory activity of 5-HI mediated by Nrf2 is independent of redox control. Furthermore, when injected into mice with 5-HI, the expression of Nrf2 was significantly increased, and the LPS-induced mRNA expression of CXCL1, CCL2, TNFα, and IL-6 were remarkably inhibited in the kidneys, liver, and lungs, and the production of these cytokines in serum was effectively reduced. Collectively, these results suggest that 5-HI has potential in the treatment of inflammatory diseases through the activation of Nrf2. Copyright © 2018. Published by Elsevier Inc.

C-glycosylflavones from the aerial parts of Eleusine indica inhibit LPS-induced mouse lung inflammation.

PubMed

De Melo, Giany O; Muzitano, Michelle F; Legora-Machado, Alexandre; Almeida, Thais A; De Oliveira, Daniela B; Kaiser, Carlos R; Koatz, Vera Lucia G; Costa, Sônia S

2005-04-01

The infusion of aerial parts (EI) of Eleusine indica Gaertn (Poaceae) is used in Brazil against airway inflammatory processes like influenza and pneumonia. Pre-treatment with 400 mg/kg of crude extract inhibited 98% of lung neutrophil recruitment in mice exposed to aerosols of lipopolysaccharide (LPS) from Gram-negative bacteria, in a dose-dependent manner. At 400 microg/kg, schaftoside (6-C-beta-glucopyranosyl-8-C-alpha-arabinopyranosylapigenin) and vitexin (8-C-beta-glucopyranosylapigenin), isolated from EI, inhibited 62% and 80% of lung neutrophil influx, respectively. These results may justify the popular use of E. indica against airway inflammatory processes.

Attenuation of lipopolysaccharide (LPS)-induced cytotoxicity by tocopherols and tocotrienols.

PubMed

Nishio, Keiko; Horie, Masanori; Akazawa, Yoko; Shichiri, Mototada; Iwahashi, Hitoshi; Hagihara, Yoshihisa; Yoshida, Yasukazu; Niki, Etsuo

2013-01-01

Lipopolysaccharide (LPS) induces host inflammatory responses and tissue injury and has been implicated in the pathogenesis of various age-related diseases such as acute respiratory distress syndrome, vascular diseases, and periodontal disease. Antioxidants, particularly vitamin E, have been shown to suppress oxidative stress induced by LPS, but the previous studies with different vitamin E isoforms gave inconsistent results. In the present study, the protective effects of α- and γ-tocopherols and α- and γ-tocotrienols on the oxidative stress induced by LPS against human lung carcinoma A549 cells were studied. They suppressed intracellular reactive oxygen formation, lipid peroxidation, induction of inflammatory mediator cytokines, and cell death. Tocopherols were incorporated into cultured cells much slower than tocotrienols but could suppress LPS-induced oxidative stress at much lower intracellular concentration than tocotrienols. Considering the bioavailability, it was concluded that α-tocopherol may exhibit the highest protective capacity among the vitamin E isoforms against LPS-induced oxidative stress.

Protective effect of naringin against the LPS-induced apoptosis of PC12 cells: Implications for the treatment of neurodegenerative disorders

PubMed Central

Wang, Hui; Xu, You Song; Wang, Miao Lin; Cheng, Chao; Bian, Rui; Yuan, Hao; Wang, Yi; Guo, Ting; Zhu, Lin Lin; Zhou, Hang

2017-01-01

Several studies have demonstrated that increased apoptosis plays an essential role in neurodegenerative disorders. It has been demonstrated that lipopolysaccharide (LPS) induces apoptosis largely through the production of intracellular reactive oxygen species (ROS) and inflammatory mediators. In this study, we investigated the potential protective mechanisms of naringin (Nar), a pummelo peel extract, on LPS-induced PC12 cell apoptosis. Nar pre-conditioning prior to stimulation with LPS for 18 h was a prerequisite for evaluating PC12 cell viability and the protective mechanisms of Nar. Nar significantly improved cell survival in a time- and concentration-dependent manner. On the one hand, Nar downregulated cytochrome P450 2E1 (CYP2E1), inhibited the release of ROS, mitigated the stimulation of oxidative stress, and rectified the antioxidant protein contents of nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1), superoxide dismutase (SOD)2 and glutathione synthetase (GSS). On the other hand, Nar down-regulated inflammatory gene and protein expression, including interleukin (IL)-1β, IL-6, tumor necrosis factor (TNF)-α, HMGB1, high mobility group box 1 protein (HMGB1), cyclo-oxygenase-2 (COX-2), the Toll-like receptor 4 (TLR4)-myeloid differentiation factor 88 (MyD88)-TNF receptor-associated factor 6 (TRAF6) path way and downstream mitogen activated protein kinase (MAPK) phosphorylation, activator protein transcription factor-1 (AP-1) and nuclear factor (NF)-κB. Moroever, Nar markedly attenuated the cytochrome c shift from the mitochondria to the cytosol and regulated caspase-3-related protein expression. To the best of our knowledge, this is the first study to report the antioxidant, anti-inflammatory and anti-apoptotic effects of Nar in neuronal-like PC12 cells. These results suggest that Nar can be utilized as a potential drug for the treatment of neurodegenerative disorders. PMID:28260042

Edaravone abrogates LPS-induced behavioral anomalies, neuroinflammation and PARP-1.

PubMed

Sriram, Chandra Shaker; Jangra, Ashok; Gurjar, Satendra Singh; Mohan, Pritam; Bezbaruah, Babul Kumar

2016-02-01

Poly(ADP-ribose) polymerase-1 (PARP-1) is a DNA nick-sensor enzyme that functions at the center of cellular stress response and affects the immune system at several key points, and thus modulates inflammatory diseases. Our previous study demonstrated that lipopolysaccharide (LPS)-induced depressive-like behavior in mice can be ameliorated by 3-aminobenzamide, which is a PARP-1 inhibitor. In the present study we've examined the effect of a free radical scavenger, edaravone pretreatment against LPS-induced anxiety and depressive-like behavior as well as various hippocampal biochemical parameters including PARP-1. Male Swiss albino mice were treated with edaravone (3 & 10mg/kgi.p.) once daily for 14days. On the 14th day 30min after edaravone treatment mice were challenged with LPS (1mg/kgi.p.). After 3h and 24h of LPS administration we've tested mice for anxiety and depressive-like behaviors respectively. Western blotting analysis of PARP-1 in hippocampus was carried out after 12h of LPS administration. Moreover, after 24h of LPS administration serum corticosterone, hippocampal BDNF, oxido-nitrosative stress and pro-inflammatory cytokines were estimated by ELISA. Results showed that pretreatment of edaravone (10mg/kg) ameliorates LPS-induced anxiety and depressive-like behavior. Western blotting analysis showed that LPS-induced anomalous expression of PARP-1 significantly reverses by the pretreatment of edaravone (10mg/kg). Biochemical analyses revealed that LPS significantly diminishes BDNF, increases pro-inflammatory cytokines and oxido-nitrosative stress in the hippocampus. However, pretreatment with edaravone (10mg/kg) prominently reversed all these biochemical alterations. Our study emphasized that edaravone pretreatment prevents LPS-induced anxiety and depressive-like behavior, mainly by impeding the inflammation, oxido-nitrosative stress and PARP-1 overexpression. Copyright © 2015. Published by Elsevier Inc.

Association of Lyn kinase with membrane rafts determines its negative influence on LPS-induced signaling

PubMed Central

Borzęcka-Solarz, Kinga; Dembińska, Justyna; Hromada-Judycka, Aneta; Traczyk, Gabriela; Ciesielska, Anna; Ziemlińska, Ewelina; Świątkowska, Anna; Kwiatkowska, Katarzyna

2017-01-01

Lipopolysaccharide (LPS) is the component of Gram-negative bacteria that activates Toll-like receptor 4 (TLR4) to trigger proinflammatory responses. We examined the involvement of Lyn tyrosine kinase in TLR4 signaling of macrophages, distinguishing its catalytic activity and intermolecular interactions. For this, a series of Lyn-GFP constructs bearing point mutations in particular domains of Lyn were overexpressed in RAW264 macrophage-like cells or murine peritoneal macrophages, and their influence on LPS-induced responses was analyzed. Overproduction of wild-type or constitutively active Lyn inhibited production of TNF-α and CCL5/RANTES cytokines and down-regulated the activity of NFκB and IRF3 transcription factors in RAW264 cells. The negative influence of Lyn was nullified by point mutations of Lyn catalytic domain or Src homology 2 (SH2) or SH3 domains or of the cysteine residue that undergoes LPS-induced palmitoylation. Depending on the cell type, overproduction of those mutant forms of Lyn could even up-regulate LPS-induced responses, and this effect was reproduced by silencing of endogenous Lyn expression. Simultaneously, the Lyn mutations blocked its LPS-induced accumulation in the raft fraction of RAW264 cells. These data indicate that palmitoylation, SH2- and SH3-mediated intermolecular interactions, and the catalytic activity of Lyn are required for its accumulation in rafts, thereby determining the negative regulation of TLR4 signaling. PMID:28228554

Necroptosis suppresses inflammation via termination of TNF- or LPS-induced cytokine and chemokine production.

PubMed

Kearney, C J; Cullen, S P; Tynan, G A; Henry, C M; Clancy, D; Lavelle, E C; Martin, S J

2015-08-01

TNF promotes a regulated form of necrosis, called necroptosis, upon inhibition of caspase activity in cells expressing RIPK3. Because necrosis is generally more pro-inflammatory than apoptosis, it is widely presumed that TNF-induced necroptosis may be detrimental in vivo due to excessive inflammation. However, because TNF is intrinsically highly pro-inflammatory, due to its ability to trigger the production of multiple cytokines and chemokines, rapid cell death via necroptosis may blunt rather than enhance TNF-induced inflammation. Here we show that TNF-induced necroptosis potently suppressed the production of multiple TNF-induced pro-inflammatory factors due to RIPK3-dependent cell death. Similarly, necroptosis also suppressed LPS-induced pro-inflammatory cytokine production. Consistent with these observations, supernatants from TNF-stimulated cells were more pro-inflammatory than those from TNF-induced necroptotic cells in vivo. Thus necroptosis attenuates TNF- and LPS-driven inflammation, which may benefit intracellular pathogens that evoke this mode of cell death by suppressing host immune responses.

Necroptosis suppresses inflammation via termination of TNF- or LPS-induced cytokine and chemokine production

PubMed Central

Kearney, C J; Cullen, S P; Tynan, G A; Henry, C M; Clancy, D; Lavelle, E C; Martin, S J

2015-01-01

TNF promotes a regulated form of necrosis, called necroptosis, upon inhibition of caspase activity in cells expressing RIPK3. Because necrosis is generally more pro-inflammatory than apoptosis, it is widely presumed that TNF-induced necroptosis may be detrimental in vivo due to excessive inflammation. However, because TNF is intrinsically highly pro-inflammatory, due to its ability to trigger the production of multiple cytokines and chemokines, rapid cell death via necroptosis may blunt rather than enhance TNF-induced inflammation. Here we show that TNF-induced necroptosis potently suppressed the production of multiple TNF-induced pro-inflammatory factors due to RIPK3-dependent cell death. Similarly, necroptosis also suppressed LPS-induced pro-inflammatory cytokine production. Consistent with these observations, supernatants from TNF-stimulated cells were more pro-inflammatory than those from TNF-induced necroptotic cells in vivo. Thus necroptosis attenuates TNF- and LPS-driven inflammation, which may benefit intracellular pathogens that evoke this mode of cell death by suppressing host immune responses. PMID:25613374

Houttuynia cordata Thunb. volatile oil exhibited anti-inflammatory effects in vivo and inhibited nitric oxide and tumor necrosis factor-α production in LPS-stimulated mouse peritoneal macrophages in vitro.

PubMed

Li, Weifeng; Fan, Ting; Zhang, Yanmin; Fan, Te; Zhou, Ping; Niu, Xiaofeng; He, Langchong

2013-11-01

Houttuynia cordata Thunb. (HC) is a medicinal herb that generally used in traditional Chinese medicine for treating allergic inflammation. The present study investigated the inhibitory effect of the volatile oil from HC Thunb. on animal models of inflammation and the production of inflammatory mediators in vivo and in vitro. In vivo, xylene-induced mouse ear edema, formaldehyde-induced paw edema and carrageenan-induced mice paw edema were significantly decreased by HC volatile oil. HC volatile oil showed pronounced inhibition of prostaglandin (PG) E2 and malondialdehyde production in the edematous exudates. In vitro exposure of mouse resident peritoneal macrophages to 1, 10, 100 and 1000 µg/mL of HC volatile oil significantly suppressed lipopolysaccharide (LPS)-stimulated production of NO and tumor necrosis factor-α (TNF-α) in a dose-dependent manner. Exposure to HC volatile oil had no effect on cell viability and systemic toxicity. Furthermore, HC volatile oil inhibited the production of NO and TNF-α by down-regulating LPS-stimulated iNOS and TNF-α mRNA expression. Western blot analysis showed that HC volatile oil attenuated LPS-stimulated synthesis of iNOS and TNF-α protein in the macrophages, in parallel. These findings add a novel aspect to the biological profile of HC and clarify its anti-inflammatory mechanism. Copyright © 2012 John Wiley & Sons, Ltd.

Inhibition of EphA2/EphrinA1 signal attenuates lipopolysaccharide-induced lung injury.

PubMed

Hong, Ji Young; Shin, Mi Hwa; Douglas, Ivor S; Chung, Kyung Soo; Kim, Eun Young; Jung, Ji Ye; Kang, Young Ae; Kim, Se Kyu; Chang, Joon; Kim, Young Sam; Park, Moo Suk

2016-11-01

Eph-Ephrin signalling mediates various cellular processes, including vasculogenesis, angiogenesis, cell migration, axon guidance, fluid homoeostasis and repair after injury. Although previous studies have demonstrated that stimulation of the EphA receptor induces increased vascular permeability and inflammatory response in lung injury, the detailed mechanisms of EphA2 signalling are unknown. In the present study, we evaluated the role of EphA2 signalling in mice with lipopolysaccharide (LPS)-induced lung injury. Acute LPS exposure significantly up-regulated EphA2 and EphrinA1 expression. Compared with LPS+IgG mice (IgG instillation after LPS exposure), LPS+EphA2 mAb mice [EphA2 monoclonal antibody (mAb) instillation posttreatment after LPS exposure] had attenuated lung injury and reduced cell counts and protein concentration of bronchoalveolar lavage fluid (BALF). EphA2 mAb posttreatment down-regulated the expression of phosphoinositide 3-kinases (PI3K) 110γ, phospho-Akt, phospho-NF-κB p65, phospho-Src and phospho-S6K in lung lysates. In addition, inhibiting the EphA2 receptor augmented the expression of E-cadherin, which is involved in cell-cell adhesion. Our study identified EphA2 receptor as an unrecognized modulator of several signalling pathways-including PI3K-Akt-NF-kB, Src-NF-κB, E-cadherin and mTOR-in LPS-induced lung injury. These results suggest that EphA2 receptor inhibitors may function as novel therapeutic agents for LPS-induced lung injury. © 2016 The Author(s). published by Portland Press Limited on behalf of the Biochemical Society.

Transiently enhanced LPS-induced fever following hyperthermic stress in rabbits

NASA Astrophysics Data System (ADS)

Shibata, Masaaki; Uno, Tadashi; Riedel, Walter; Nishimaki, Michiyo; Watanabe, Kaori

2005-11-01

Hyperthermia has been shown to induce an enhanced febrile response to the bacterial-derived endotoxin lipopolysaccharide (LPS). The aim of the present study was to test the hypothesis that the enhanced LPS-induced fever seen in heat stressed (HS) animals is caused by leakage of intestinal bacterial LPS into the circulation. Male rabbits were rendered transiently hyperthermic (a maximum rectal temperature of 43°C) and divided into three groups. They were then allowed to recover in a room at 24°C for 1, 2 or 3 days post-HS. One day after injection with LPS, the post-HS rabbits exhibited significantly higher fevers than the controls, though this was not seen in rabbits at either 2 or 3 days post-HS. The plasma levels of endogenous LPS were significantly increased during the HS as compared to those seen in normothermic rabbits prior to HS. LPS fevers were not induced in these animals. One day post-HS, rabbits that had been pretreated with oral antibiotics exhibited significantly attenuated LPS levels. When challenged with human recombinant interleukin-1β instead of LPS, the 1-day post-HS rabbits did not respond with enhanced fevers. The plasma levels of TNFα increased similarly during LPS-induced fevers in both the control and 1-day post-HS rabbits, while the plasma levels of corticosterone and the osmolality of the 1-day post-HS rabbits showed no significant differences to those seen prior to the HS. These results suggest that the enhanced fever in the 1-day post-HS rabbits is LPS specific, and may be caused by increased leakage of intestinal endotoxin into blood circulation.

Interleukin-35 Inhibits Endothelial Cell Activation by Suppressing MAPK-AP-1 Pathway.

PubMed

Sha, Xiaojin; Meng, Shu; Li, Xinyuan; Xi, Hang; Maddaloni, Massimo; Pascual, David W; Shan, Huimin; Jiang, Xiaohua; Wang, Hong; Yang, Xiao-feng

2015-07-31

Vascular response is an essential pathological mechanism underlying various inflammatory diseases. This study determines whether IL-35, a novel responsive anti-inflammatory cytokine, inhibits vascular response in acute inflammation. Using a mouse model of LPS-induced acute inflammation and plasma samples from sepsis patients, we found that IL-35 was induced in the plasma of mice after LPS injection as well as in the plasma of sepsis patients. In addition, IL-35 decreased LPS-induced proinflammatory cytokines and chemokines in the plasma of mice. Furthermore, IL-35 inhibited leukocyte adhesion to the endothelium in the vessels of lung and cremaster muscle and decreased the numbers of inflammatory cells in bronchoalveolar lavage fluid. Mechanistically, IL-35 inhibited the LPS-induced up-regulation of endothelial cell (EC) adhesion molecule VCAM-1 through IL-35 receptors gp130 and IL-12Rβ2 via inhibition of the MAPK-activator protein-1 (AP-1) signaling pathway. We also found that IL-27, which shares the EBI3 subunit with IL-35, promoted LPS-induced VCAM-1 in human aortic ECs and that EBI3-deficient mice had similar vascular response to LPS when compared with that of WT mice. These results demonstrated for the first time that inflammation-induced IL-35 inhibits LPS-induced EC activation by suppressing MAPK-AP1-mediated VCAM-1 expression and attenuates LPS-induced secretion of proinflammatory cytokines/chemokines. Our results provide insight into the control of vascular inflammation by IL-35 and suggest that IL-35 is an attractive novel therapeutic reagent for sepsis and cardiovascular diseases. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

Anthocyanins protect against LPS-induced oxidative stress-mediated neuroinflammation and neurodegeneration in the adult mouse cortex.

PubMed

Khan, Muhammad Sohail; Ali, Tahir; Kim, Min Woo; Jo, Myeung Hoon; Jo, Min Gi; Badshah, Haroon; Kim, Myeong Ok

2016-11-01

Several studies provide evidence that reactive oxygen species (ROS) are key mediators of various neurological disorders. Anthocyanins are polyphenolic compounds and are well known for their anti-oxidant and neuroprotective effects. In this study, we investigated the neuroprotective effects of anthocyanins (extracted from black soybean) against lipopolysaccharide (LPS)-induced ROS-mediated neuroinflammation and neurodegeneration in the adult mouse cortex. Intraperitoneal injection of LPS (250 μg/kg) for 7 days triggers elevated ROS and oxidative stress, which induces neuroinflammation and neurodegeneration in the adult mouse cortex. Treatment with 24 mg/kg/day of anthocyanins for 14 days in LPS-injected mice (7 days before and 7 days co-treated with LPS) attenuated elevated ROS and oxidative stress compared to mice that received LPS-injection alone. The immunoblotting results showed that anthocyanins reduced the level of the oxidative stress kinase phospho-c-Jun N-terminal Kinase 1 (p-JNK). The immunoblotting and morphological results showed that anthocyanins treatment significantly reduced LPS-induced-ROS-mediated neuroinflammation through inhibition of various inflammatory mediators, such as IL-1β, TNF-α and the transcription factor NF- k B. Anthocyanins treatment also reduced activated astrocytes and microglia in the cortex of LPS-injected mice, as indicated by reductions in GFAP and Iba-1, respectively. Anthocyanins also prevent overexpression of various apoptotic markers, i.e., Bax, cytosolic cytochrome C, cleaved caspase-3 and PARP-1. Immunohistochemical fluoro-jade B (FJB) and Nissl staining indicated that anthocyanins prevent LPS-induced neurodegeneration in the mouse cortex. Our results suggest that dietary flavonoids, such as anthocyanins, have antioxidant and neuroprotective activities that could be beneficial to various neurological disorders. Copyright © 2016 Elsevier Ltd. All rights reserved.

Piracetam Attenuates LPS-Induced Neuroinflammation and Cognitive Impairment in Rats.

PubMed

Tripathi, Alok; Paliwal, Pankaj; Krishnamurthy, Sairam

2017-11-01

The present study was performed to investigate the effect of piracetam on neuroinflammation induced by lipopolysaccharide (LPS) and resulting changes in cognitive behavior. Neuroinflammation was induced by a single dose of LPS solution infused into each of the lateral cerebral ventricles in concentrations of 1 μg/μl, at a rate of 1 μl/min over a 5-min period, with a 5-min waiting period between the two infusions. Piracetam in doses of 50, 100, and 200 mg/kg i.p. was administered 30 min before LPS infusion and continued for 9 days. On ninth day, the behavioral test for memory and anxiety was done followed by blood collection and microdissection of the hippocampus (HIP) and prefrontal cortex brain regions. Piracetam attenuated the LPS-induced decrease in coping strategy to novel environment indicating anxiolytic activity. It also reversed the LPS-induced changes in the known arm and novel arm entries in the Y-maze test indicating amelioration of spatial memory impairment. Further, piracetam moderated LPS-induced decrease in the mitochondrial complex enzyme activities (I, II, IV, and V) and mitochondrial membrane potential. It ameliorated changes in hippocampal lipid peroxidation and nitrite levels including the activity of superoxide dismutase. Piracetam region specifically ameliorated LPS-induced increase in the level of IL-6 in HIP indicating anti-neuroinflammatory effect. Further, piracetam reduced HIP Aβ (1-40) and increased blood Aβ level suggesting efflux of Aβ from HIP to blood. Therefore, the present study indicates preclinical evidence for the use of piracetam in the treatment of neuroinflammatory disorders.

The heme oxygenase-1 inducer THI-56 negatively regulates iNOS expression and HMGB1 release in LPS-activated RAW 264.7 cells and CLP-induced septic mice.

PubMed

Park, Eun Jung; Jang, Hwa Jin; Tsoyi, Konstantin; Kim, Young Min; Park, Sang Won; Kim, Hye Jung; Lee, Jae Heun; Chang, Ki Churl

2013-01-01

The nuclear DNA binding protein high mobility group box 1 (HMGB1) has recently been suggested to act as a late mediator of septic shock. The effect of ((S)-6,7-dihydroxy-1-(4-hydroxynaphthylmethyl)-1,2,3,4-tetrahydroisoquinoline alkaloid, also known as THI-56, in an experimental model of sepsis was investigated. THI-56 exhibited potent anti-inflammatory properties in response to LPS in RAW 264.7 cells. In particular, THI-56 significantly inhibited the expression of inducible nitric oxide synthase (iNOS) and the release of HMGB1 in activated macrophages. THI-56 activated NE-F2-regulated factor 2 (Nrf-2)/heme oxygenase 1 (HO-1). The specific knockdown of the HO-1 gene by HO-1 siRNA significantly reversed the inhibitory effects of THI-56 on iNOS expression and HMGB1 release in LPS-stimulated macrophages. Importantly, THI-56 administration protected animals from death induced by either a lethal dose of LPS or cecal ligation and puncture (CLP). Furthermore, the ALT, AST, BUN, creatinine, and HMGB1 levels in the blood were significantly increased in CLP-induced septic mice, and the administration of THI-56 reduced these levels in a concentration-dependent and zinc protoporphyrin IX (ZnPPIX)-sensitive manner. In addition, the administration of THI-56 significantly ameliorated not only lung damage but also macrophage infiltration in the livers of CLP-induced septic mice, and these effects were also abrogated in the presence of ZnPPIX. Thus, we conclude that THI-56 significantly attenuates the proinflammatory response induced by LPS and reduces organ damage in a CLP-induced sepsis model through the upregulation of Nrf-2/HO-1.

Contribution of sensory nerves to LPS-induced hyperresponsiveness of human isolated bronchi.

PubMed

Calzetta, Luigino; Luongo, Livio; Cazzola, Mario; Page, Clive; Rogliani, Paola; Facciolo, Francesco; Maione, Sabatino; Capuano, Annalisa; Rinaldi, Barbara; Matera, Maria Gabriella

2015-06-15

Bacterial lipopolysaccharide (LPS) can induce bronchial hyperresponsiveness (BHR), but the underlying mechanisms remain to be determined. Here, the possible contribution of sensory nerves to LPS-induced BHR was examined in human isolated bronchi to pharmacologically identify the mechanisms underlying this phenomenon. Human isolated bronchial tone was induced by electrical field stimulation (EFS). The responses of airways to LPS, with or without capsaicin desensitization or thiorphan treatment were studied and the transient receptor potential vanilloid type 1 (TRPV1) expression was assessed. We performed similar experiments in the presence of a TRPV1 or a neurokinin (NK) 2 receptor antagonist using SB366791 and GR159897, respectively. LPS increased (≃2.3-fold, P<0.001) the contraction induced by EFS, compared to control tissues. Acute administration of capsaicin enhanced (≃2.3-fold, P<0.001) the EFS-mediated contraction, but did not potentiate the effect of LPS. Thiorphan increased (≃1.3-fold, P<0.05) the contractile response of LPS treated tissues and, at lower frequencies, it enhanced (≃1.7-fold, P<0.001) the capsaicin-induced contraction. In capsaicin-desensitized bronchi, LPS did not modify (P>0.05) the EFS contractile response, nor after treatment with thiorphan. Capsaicin desensitization reduced (≃0.4-fold, P<0.001) the LPS-induced BHR. SB366791 and GR159897 prevented the LPS-induced BHR and the release of NKA. LPS increased (+85.3±9.5%, P<0.01) the surface membrane expression of TRPV1 in parasympathetic ganglia. Our results demonstrate the involvement of capsaicin-sensitive sensory nerves and neutral endopeptidases in LPS-induced BHR of the human bronchi, associated with an upregulation of TRPV1 and release of NKA. Copyright © 2015. Published by Elsevier Inc.

Red ginseng marc oil inhibits iNOS and COX-2 via NFκB and p38 pathways in LPS-stimulated RAW 264.7 macrophages.

PubMed

Bak, Min-Ji; Hong, Soon-Gi; Lee, Jong-Won; Jeong, Woo-Sik

2012-11-22

In this study, we investigated the anti-inflammatory effects of red ginseng marc oil (RMO) in the RAW 264.7 macrophage cell line. RMO was prepared by a supercritical CO(2) extraction of waste product generated after hot water extraction of red ginseng. RMO significantly inhibited the production of oxidative stress molecules such as nitric oxide and reactive oxygen species in lipopolysaccharide (LPS)-activated RAW 264.7 cells. Levels of inflammatory targets including prostaglandin E2, tumor necrosis factor-α, interleukin (IL)-1β and IL-6 were also reduced after the treatment with RMO. In addition, RMO diminished the expressions of inducible nitric oxide synthase and cyclooxygenase 2 at both mRNA and protein levels. Blockade of nuclear translocation of the p65 subunit of nuclear factor κB (NFκB) was also observed after the treatment of RMO. Furthermore, RMO decreased the phosphorylations of p38 mitogen-activated protein kinase (MAPK) and its upstream kinases including MAPK kinases 3/6 (MKK3/6) and TAK 1 (TGF-β activated kinase 1). Gas chromatographic analysis on RMO revealed that RMO contained about 10% phytosterols including sitosterol, stigmasterol and campesterol which may contribute to the anti-inflammatory properties of RMO. Taken together, these results suggest that the anti-inflammatory effect of RMO in LPS-induced RAW 264.7 macrophages could be associated with the inhibition of NFκB transcriptional activity, possibly via blocking the p38 MAPK pathway.

Ebselen suppresses inflammation induced by Helicobacter pylori lipopolysaccharide via the p38 mitogen-activated protein kinase signaling pathway.

PubMed

Xu, Ling; Gong, Changguo; Li, Guangming; Wei, Jue; Wang, Ting; Meng, Wenying; Shi, Min; Wang, Yugang

2018-05-01

Ebselen is a seleno-organic compound that has been demonstrated to have antioxidant and anti-inflammatory properties. A previous study determined that ebselen inhibits airway inflammation induced by inhalational lipopolysaccharide (LPS), however, the underlying molecular mechanism remains to be elucidated. The present study investigated the effect of ebselen on the glutathione peroxidase (GPX)‑reactive oxygen species (ROS) pathway and interleukin‑8 (IL‑8) expression induced by Helicobacter pylori LPS in gastric cancer (GC) cells. Cells were treated with 200 ng/ml H. pylori‑LPS in the presence or absence of ebselen for various durations and concentrations (µmol/l). The expression of toll‑like receptor 4 (TLR4), GPX2, GPX4, p38 mitogen‑activated protein kinase (p38 MAPK), phosphorylated‑p38 MAPK, ROS production and IL‑8 expression were detected with western blotting or ELISA. The present study revealed that TLR4 expression was upregulated; however, GPX2 and GPX4 expression was reduced following treatment with H. pylori LPS, which led to increased ROS production, subsequently altering the IL‑8 expression level in GC cells. Additionally, it was determined that ebselen prevented the reduction in GPX2/4 levels induced by H. pylori LPS, however, TLR4 expression was not affected. Ebselen may also block the expression of IL‑8 by inhibiting phosphorylation of p38 MAPK. These data suggest ebselen may inhibit ROS production triggered by H. pylori LPS treatment via GPX2/4 instead of TLR4 signaling and reduce phosphorylation of p38 MAPK, resulting in altered production of IL‑8. Ebselen may, therefore, be a potential therapeutic agent to mediate H. pylori LPS-induced cell damage.

[Molecular mechanism involved in adhesion of monocytes to endothelial cells induced by nicotine and Porphyromonas gingivalis-LPS].

PubMed

Wang, Yi-xiang; An, Na; Ouyang, Xiang-ying

2015-10-18

To investigate molecular mechanism involved in nicotine in combination with Porphyromonas gingivalis (P.g) caused monocyte-endothelial cell adhesion. The effect of nicotine, P.g-lipopolysaccharide (P.g-LPS) and their combination on the proliferation of U937 cells was determined by CCK-8 method. Interleukin-6 (IL-6) expression was investigated by real-time PCR after U937 cells were treated with nicotine, P.g-LPS and their combination. In human umbilical vein endothelial cells (HUVECs), the expressions of monocyte chemoattractant protein CCL-8 and adhesion molecules including vascular cell adhesion molecule 1 (Vcam-1), very late antigen 4 alpha (VLA4α), tumor necrosis factor receptor superfamily member 4 (OX40) and OX40 ligand (OX40L) were detected by real-time PCR or Western blotting assays after HUVEC cells were treated with nicotine, P.g-LPS and their combination. Adhesion of monocytes to endothelial cells was detected after the HUVECs and U937 cells were stimulated with nicotine, P.g-LPS and their combination, respectively. P.g-LPS did not affect the proliferative ability of nicotine in U937 cells. However, the ability of P.g-LPS induced IL-6 expression was inhibited by 100 μmol/L nicotine in U937 cells. In HUVECs, the expressions of CCL-8, Vcam-1, VLA4α, OX40 and OX40L were significantly up-regulated by nicotine and P.g-LPS combination compared with nicotine alone, P.g-LPS alone and the untreated control. Adhesion of monocytes to HUVECs results showed that the two types of cells treated with nicotine in combination with P.g-LPS could markedly increase the adhesion ability of monocytes to HUVECs. P.g-LPS in combination with nicotine could recruit monocytes to endothelial lesion through up-regulation of CCL-8, and promote adhesion of monocytes to endothelial cells through enhancement of Vcam-1/VLA4α and OX40/OX40L interactions, which could be involved in the initiation and development of atherosclerosis.

Myeloid-derived NF-κB negative regulation of PU.1 and cEBPβ-driven pro-inflammatory cytokine production restrains LPS-induced Shock

PubMed Central

Vanoni, Simone; Tsai, Yi Ting; Waddell, Amanda; Waggoner, Lisa; Klarquist, Jared; Divanovic, Senad; Hoebe, Kasper; Steinbrecher, Kris A.; Hogan, Simon P.

2017-01-01

Sepsis is a life-threatening event predominantly caused by gram-negative bacteria. Bacterial infection causes a pronounced macrophage (MΦ) and dendritic cell (DC) activation that leads to excessive pro-inflammatory cytokine interleukin (IL)-1β, IL-6, and Tumor necrosis factor (TNF)-α production (cytokine storm), resulting in endotoxic shock. Previous experimental studies have revealed that inhibiting Nuclear Factor kappa Beta (NF-κB) signaling ameliorates disease symptoms; however, the contribution of myeloid p65 in endotoxic shock remains elusive. In this study, we demonstrate increased mortality in mice lacking p65 in the myeloid lineage (p65Δmye) compared to wild type (WT) mice upon ultra-pure LPS (U-LPS) challenge. We show that increased susceptibility to Lipopolysaccharide (LPS)-induced shock was associated with elevated serum level of IL-1β and IL-6. Mechanistic analyses revealed that LPS-induced pro-inflammatory cytokine production was ameliorated in p65-deficient bone marrow–derived macrophages (BMDMs); however, p65-deficient “activated” peritoneal macrophages (MΦs) exhibited elevated IL-1β and IL-6. We show that the elevated pro-inflammatory cytokine secretion was due in part to increased accumulation of IL-1β mRNA and protein in activated inflammatory MΦs. The increased IL-1β was linked with heightened binding of PU.1 and CCAAT/Enhancer Binding Protein Beta (cEBPβ to Il1b and Il6 promoters in activated inflammatory MΦs. Our data provides insight into a role for NF-κB in the negative regulation of pro-inflammatory cytokines in myeloid cells. PMID:27932520

LPS-induced expression of CD14 in the TRIF pathway is epigenetically regulated by sulforaphane in porcine pulmonary alveolar macrophages.

PubMed

Yang, Qin; Pröll, Maren J; Salilew-Wondim, Dessie; Zhang, Rui; Tesfaye, Dawit; Fan, Huitao; Cinar, Mehmet U; Große-Brinkhaus, Christine; Tholen, Ernst; Islam, Mohammad A; Hölker, Michael; Schellander, Karl; Uddin, Muhammad J; Neuhoff, Christiane

2016-11-01

Pulmonary alveolar macrophages (AMs) are important in defense against bacterial lung inflammation. Cluster of differentiation 14 (CD14) is involved in recognizing bacterial lipopolysaccharide (LPS) through MyD88-dependent and TRIF pathways of innate immunity. Sulforaphane (SFN) shows anti-inflammatory activity and suppresses DNA methylation. To identify CD14 epigenetic changes by SFN in the LPS-induced TRIF pathway, an AMs model was investigated in vitro. CD14 gene expression was induced by 5 µg/ml LPS at the time point of 12 h and suppressed by 5 µM SFN. After 12 h of LPS stimulation, gene expression was significantly up-regulated, including TRIF, TRAF6, NF-κB, TRAF3, IRF7, TNF-α, IL-1β, IL-6, and IFN-β. LPS-induced TRAM, TRIF, RIPK1, TRAF3, TNF-α, IL-1β and IFN-β were suppressed by 5 µM SFN. Similarly, DNMT3a expression was increased by LPS but significantly down-regulated by 5 µM SFN. It showed positive correlation of CD14 gene body methylation with in LPS-stimulated AMs, and this methylation status was inhibited by SFN. This study suggests that SFN suppresses CD14 activation in bacterial inflammation through epigenetic regulation of CD14 gene body methylation associated with DNMT3a. The results provide insights into SFN-mediated epigenetic down-regulation of CD14 in LPS-induced TRIF pathway inflammation and may lead to new methods for controlling LPS-induced inflammation in pigs.

Anti-inflammatory evaluation of the methanolic extract of Taraxacum officinale in LPS-stimulated human umbilical vein endothelial cells.

PubMed

Jeon, Daun; Kim, Seok Joong; Kim, Hong Seok

2017-11-29

Atherosclerosis is a chronic vascular inflammatory disease. Since even low-level endotoxemia constitutes a powerful and independent risk factor for the development of atherosclerosis, it is important to find therapies directed against the vascular effects of endotoxin to prevent atherosclerosis. Taraxacum officinale (TO) is used for medicinal purposes because of its choleretic, diuretic, antioxidative, anti-inflammatory, and anti-carcinogenic properties, but its anti-inflammatory effect on endothelial cells has not been established. We evaluated the anti-inflammatory activity of TO filtered methanol extracts in LPS-stimulated human umbilical vein endothelial cells (HUVECs) by monocyte adhesion and western blot assays. HUVECs were pretreated with 100 μg/ml TO for 1 h and then incubated with 1 μg/ml LPS for 24 h. The mRNA and protein expression levels of the targets (pro-inflammatory cytokines and adhesion molecules) were analyzed by real-time PCR and western blot assays. We also preformed HPLC analysis to identify the components of the TO methanol extract. The TO filtered methanol extracts dramatically inhibited LPS-induced endothelial cell-monocyte interactions by reducing vascular cell adhesion molecule-1 and monocyte chemoattractant protein-1, and pro-inflammatory cytokine expression. TO suppressed the LPS-induced nuclear translocation of NF-κB, whereas it did not affect MAPK activation. Our findings demonstrated that methanol extracts of TO could attenuate LPS-induced endothelial cell activation by inhibiting the NF-κB pathway. These results indicate the potential clinical benefits and applications of TO for the prevention of vascular inflammation and atherosclerosis.

Sulforaphane suppresses LPS-induced or TPA-induced downregulation of PDCD4 in RAW 264.7 cells.

PubMed

Cho, Jong-Ho; Kim, Young-Woo; Keum, Young-Sam

2014-11-01

Sulforaphane is a natural chemopreventive isothiocyanate and abundantly found in various cruciferous vegetables. Although chemopreventive activity of sulforaphane is well documented, the detailed biochemical mechanism(s), underlying how it regulates the protein translation process to antagonize pro-inflammatory responses are largely unclear. In the present study, we show that lipopolysaccharide (LPS) or 12-O-tetradecanoylphorbol-13-acetate (TPA) treatment reduces cellular levels of PDCD4, and this event is mediated by affecting both transcription and proteolysis in RAW 264.7 cells. We show that LPS-mediated or TPA-mediated PDCD4 downregulation is catalyzed by the activation of intracellular Akt1 or S6K1 kinases and that sulforaphane suppresses LPS-induced or TPA-induced Akt1 or S6K1 activation, thereby resulting in the attenuation of PDCD4 downregulation in RAW 264.7 cells. We propose that sulforaphane suppression of PDCD4 downregulation serves as a novel molecular mechanism to control proliferation in response to pro-inflammatory signals. Copyright © 2014 John Wiley & Sons, Ltd.

Dangguishaoyao-San attenuates LPS-induced neuroinflammation via the TLRs/NF-κB signaling pathway.

PubMed

Ding, Rui-Rui; Chen, Wang; Guo, Cong-Ying; Liao, Wei-Tao; Yang, Xia; Liao, Feng-Er; Lin, Jing-Ming; Mei, Han-Fang; Zeng, Yu

2018-05-29

Dangguishaoyao-San (DSS) is composed of six traditional Chinese medicines, including Angelica sinensis, Paeoniae radix, Rhizoma Ligusticum, Poria cocos, Rhizoma Atractylodis Macrocephalae, and Rhizoma Alismatis. DSS has been reported to be effective in alleviating the symptoms of Alzheimer's disease (AD). The aim of this study was to investigate the mechanism of action of DSS in vitro using lipopolysaccharide (LPS)-stimulated BV-2 microglia cells. BV-2 cells were pretreated with 0.58-1.16 mg/mL of DSS for 2 h and then treated with 1 μg/mL LPS for 24 h. Cell viability was determined by an 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The protein expression levels were measured by Western blots. Inflammatory factors were detected by enzyme-linked immunosorbent assays (ELISAs). The mRNA levels of inflammatory factors were analyzed by quantitative real-time PCR (qRT-PCR). DSS treatment at concentrations of 0.58-1.16 mg/mL resulted in no significant cytotoxicity. DSS attenuated the release of pro-inflammatory factors, such as interleukin-1β (IL-1β), iNOS and tumor necrosis factor-α (TNF-α) in LPS-induced BV-2 cells. DSS attenuated the mRNA expression of pro-inflammatory cytokines, TLR2, and TLR4 and decreased TLR4 and TLR protein levels as well as the phosphorylation of IκB in LPS-induced BV-2 cells. DSS also down-regulated the nuclear translocation of p65. This study demonstrated that DSS has a protective effect on neuroinflammation in LPS-induced BV-2 microglia cells through the TLRs/NF-κB signaling pathway. Copyright © 2018. Published by Elsevier Masson SAS.

Osthole inhibits inflammatory cytokine release through PPARα/γ-mediated mechanisms in LPS-stimulated 3T3-L1 adipocytes.

PubMed

Wang, Xiao-li; Shang, Xiang; Cui, Yan; Zhao, Xi; Zhang, Yan; Xie, Mei-lin

2015-04-01

Peroxisome proliferator-activated receptor (PPAR) α/γ may control inflammatory response by regulating the nuclear factor-kappa B (NF-κB). Osthole may be a dual agonist of PPARα/γ, but whether or not osthole may inhibit inflammatory cytokines in cultured 3T3-L1 adipocytes is unclear. We investigated the action of osthole and its potential mechanisms in lipopolysaccharide (LPS)-stimulated 3T3-L1 adipocytes. The 3T3-L1 adipocytes stimulated with LPS were cultured and treated with different concentrations of osthole. The inflammatory cytokines including tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in cultured supernatants were detected by the enzyme-linked immunosorbent assay (ELISA) method, and the protein expressions of PPARα/γ and NF-κB p65 in adipocytes were detected by the Western blot method, respectively. Following treatment of adipocytes with osthole 0.1-1.6 μM, the TNF-α and IL-6 levels in cultured supernatants were decreased, and the NF-κB p65 protein expression in adipocytes was also decreased, while the PPARα/γ protein expressions were increased. After pretreatment of adipocytes with specific inhibitor(s) of PPARα and /or PPARγ, the inhibitory effects of osthole on TNF-α and IL-6 were decreased or almost cancelled, and the effects on NF-κB p65 protein expression also exhibited similar variations. Osthole could inhibit the TNF-α and IL-6 production in LPS-stimulated adipocytes, and its mechanism might be related to reduction of NF-κB expression via activation of PPARα/γ.

LPS Increases 5-LO Expression on Monocytes via an Activation of Akt-Sp1/NF-κB Pathways.

PubMed

Lee, Seung Jin; Seo, Kyo Won; Kim, Chi Dae

2015-05-01

5-Lipoxygenase (5-LO) plays a pivotal role in the progression of atherosclerosis. Therefore, this study investigated the molecular mechanisms involved in 5-LO expression on monocytes induced by LPS. Stimulation of THP-1 monocytes with LPS (0~3 µg/ml) increased 5-LO promoter activity and 5-LO protein expression in a concentration-dependent manner. LPS-induced 5-LO expression was blocked by pharmacological inhibition of the Akt pathway, but not by inhibitors of MAPK pathways including the ERK, JNK, and p38 MAPK pathways. In line with these results, LPS increased the phosphorylation of Akt, suggesting a role for the Akt pathway in LPS-induced 5-LO expression. In a promoter activity assay conducted to identify transcription factors, both Sp1 and NF-κB were found to play central roles in 5-LO expression in LPS-treated monocytes. The LPS-enhanced activities of Sp1 and NF-κB were attenuated by an Akt inhibitor. Moreover, the LPS-enhanced phosphorylation of Akt was significantly attenuated in cells pretreated with an anti-TLR4 antibody. Taken together, 5-LO expression in LPS-stimulated monocytes is regulated at the transcriptional level via TLR4/Akt-mediated activations of Sp1 and NF-κB pathways in monocytes.

Antagonistic effects of acetylshikonin on LPS-induced NO and PGE2 production in BV2 microglial cells via inhibition of ROS/PI3K/Akt-mediated NF-κB signaling and activation of Nrf2-dependent HO-1.

PubMed

Jayasooriya, Rajapaksha Gedara Prasad Tharanga; Lee, Kyoung-Tae; Choi, Yung Hyun; Moon, Sung-Kwon; Kim, Wun-Jae; Kim, Gi-Young

2015-10-01

Although acetylshikonin (ACS) is known to have antioxidant and antitumor activities, whether ACS regulates the expression of proinflammatory mediators in lipopolysaccharide (LPS)-stimulated microglial cells remains unclear. In this study, it was found that ACS isolated from Lithospermum erythrorhizon inhibits LPS-induced nitric oxide (NO) and prostaglandin E2 (PGE2) release by suppressing the expression of inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2) in BV2 microglial cells. Furthermore, ACS reduced the LPS-induced DNA-binding activity of nuclear factor-κB (NF-κB) and subsequently suppressed iNOS and COX-2 expression. Consistent with these data, ACS attenuated the phosphorylation of PI3K and Akt and suppressed the DNA-binding activity of NF-κB by inducing the generation of reactive oxygen species (ROS) in LPS-stimulated cells. In addition, ACS enhanced heme oxygenase-1 (HO-1) expression via nuclear factor-erythroid 2-related factor 2 (Nrf2) activation. Zinc protoporphyrin, a specific HO-1 inhibitor, partially attenuated the antagonistic effects of ACS on LPS-induced NO and PGE2 production. By contrast, the presence of cobalt protoporphyrin, a specific HO-1 inducer, potently suppressed LPS-induced NO and PGE2 production. These data indicate that ACS downregulates proinflammatory mediators such as NO and PGE2 by suppressing PI3K/Akt-dependent NF-κB activity induced by ROS as well as inducing Nrf2-dependent HO-1 activity. Taken together, ACS might be a good candidate to regulate LPS-mediated inflammatory diseases.

Inhibition by rebamipide of cytokine-induced or lipopolysaccharide-induced chemokine synthesis in human corneal fibroblasts.

PubMed

Fukuda, Ken; Ishida, Waka; Tanaka, Hiroshi; Harada, Yosuke; Fukushima, Atsuki

2014-12-01

The dry-eye drug rebamipide has mucin secretagogue activity in and anti-inflammatory effects on corneal epithelial cells. Corneal stromal fibroblasts (transdifferentiated keratocytes) function as immune modulators in the pathogenesis of chronic ocular allergic inflammation and in innate immune responses at the ocular surface. The possible anti-inflammatory effects of rebamipide on human corneal stromal fibroblasts were examined. Serum-deprived cells were incubated for 1 h with rebamipide and then for various times in the additional absence or presence of cytokines or bacterial lipopolysaccharide (LPS). The release of chemokines into culture supernatants was determined with ELISAs. The intracellular abundance of chemokine mRNAs was quantitated by reverse transcription and real-time PCR analysis. Degradation of the nuclear factor κB (NFκB) inhibitor IκBα was detected by immunoblot analysis. Rebamipide suppressed the release of interleukin (IL)-8 and the upregulation of IL-8 mRNA induced by tumour necrosis factor α (TNF-α) or LPS in corneal fibroblasts. It also inhibited eotaxin-1 (CCL-11) expression at the protein and mRNA levels induced by the combination of TNF-α and IL-4. In addition, rebamipide attenuated the degradation of IκBα induced by TNF-α or LPS. Rebamipide inhibited the synthesis of chemokines by corneal fibroblasts in association with suppression of NFκB signalling. Rebamipide may therefore prove effective for the treatment of corneal stromal inflammation associated with allergy or bacterial infection. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Cystine improves survival rates in a LPS-induced sepsis mouse model.

PubMed

Tanaka, Kenji A K; Kurihara, Shigekazu; Shibakusa, Tetsuro; Chiba, Yasumasa; Mikami, Takashi

2015-12-01

The control of inflammation is important for suppressing severe sepsis. Oral administration of cystine and theanine have been shown to suppress inflammatory responses due to invasion. Furthermore, the uptake of cystine into monocytes is promoted by exposure to lipopolysaccharide (LPS). In the present study, the effects of cystine were examined in the context of inflammatory responses. Cystine was orally administered to mice, and the levels of interleukin (IL)-6 in the blood and spleen and the survival rates were calculated after the administration of LPS. The effects of cystine as well as neutralising anti-IL-10 antibodies on the LPS-induced production of IL-6 and IL-10 were examined in a monocyte cell line. The oral administration of cystine reduced IL-6 levels in the blood and spleen after LPS stimulation and improved survival rates. The addition of cystine to monocytes suppressed LPS-induced IL-6 production but enhanced IL-10 production. A neutralising anti-IL-10 antibody eliminated the inhibitory effects of cystine on the LPS-induced production of IL-6. The oral administration of cystine suppressed IL-6 production following LPS stimulation and improved survival rates in mice with LPS-induced sepsis. The enhanced production of IL-10 by monocytes may be involved in this anti-inflammatory response. Copyright © 2014 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

LPS-Induced Low-Grade Inflammation Increases Hypothalamic JNK Expression and Causes Central Insulin Resistance Irrespective of Body Weight Changes.

PubMed

Rorato, Rodrigo; Borges, Beatriz de Carvalho; Uchoa, Ernane Torres; Antunes-Rodrigues, José; Elias, Carol Fuzeti; Elias, Lucila Leico Kagohara

2017-07-04

Metabolic endotoxemia contributes to low-grade inflammation in obesity, which causes insulin resistance due to the activation of intracellular proinflammatory pathways, such as the c-Jun N-terminal Kinase (JNK) cascade in the hypothalamus and other tissues. However, it remains unclear whether the proinflammatory process precedes insulin resistance or it appears because of the development of obesity. Hypothalamic low-grade inflammation was induced by prolonged lipopolysaccharide (LPS) exposure to investigate if central insulin resistance is induced by an inflammatory stimulus regardless of obesity. Male Wistar rats were treated with single (1 LPS) or repeated injections (6 LPS) of LPS (100 μg/kg, IP) to evaluate the phosphorylation of the insulin receptor substrate-1 (IRS1), Protein kinase B (AKT), and JNK in the hypothalamus. Single LPS increased the expression of pIRS1, pAKT, and pJNK, whereas the repeated LPS treatment failed to recruit pIRS1 and pAKT. The 6 LPS treated rats showed increased total JNK and pJNK. The 6 LPS rats became unresponsive to the hypophagic effect induced by central insulin administration (12 μM/5 μL, ICV). Prolonged exposure to LPS (24 h) impaired the insulin-induced AKT phosphorylation and the translocation of the transcription factor forkhead box protein O1 (FoxO1) from the nucleus to the cytoplasm of the cultured hypothalamic GT1-7 cells. Central administration of the JNK inhibitor (20 μM/5 μL, ICV) restored the ability of insulin to phosphorylate IRS1 and AKT in 6 LPS rats. The present data suggest that an increased JNK activity in the hypothalamus underlies the development of insulin resistance during prolonged exposure to endotoxins. Our study reveals that weight gain is not mandatory for the development of hypothalamic insulin resistance and the blockade of proinflammatory pathways could be useful for restoring the insulin signaling during prolonged low-grade inflammation as seen in obesity.

[Effect of endotoxin pretreatment-induced glycogen synthase kinase-3 inhibition on glycogen metabolism in rat liver and the mechanism].

PubMed

Chen, Xiaole; Gong, Jianping; Xu, Faliang

2014-02-01

To investigate the changes in the functional activity of glycogen synthase kinase-3 (GSK-3) in the hepatic tissue after endotoxin (lipopolysaccharide, LPS) tolerance and explore the effects of LPS-induced GSK-3 inhibition on glycogen metabolism in the liver. Male SD rats were randomly divided into normal control, endotoxin pretreatment and GSK-3 inhibitor (lithium chloride) groups with corresponding pretreatments prior to a large dose of LPS challenge (10 mg/kg) to induce liver injury. Glycogen deposition and content in the hepatic tissue was detected using periodic acid-Schiff (PAS) staining and a glycogen quantification kit, respectively. Western blotting was performed for semi-quantitative analysis of protein level and inhibitory phosphorylation of GSK-3, and a Coomassie brilliant blue G-250-based colorimetric assay was used to detect calpain activity in the liver. Glycogen content in the liver decreased significantly after LPS challenge in all the 3 groups (P<0.05) but showed no significant difference among the groups (P>0.05). Both LPS and lithium chloride pretreatments caused a significant increase of liver glycogen content (P<0.05). LPS pretreatment induced inhibitory phosphorylation of GSK-3β (P<0.05) and partial cleavage of GSK-3α but did not affect the expression of GSK-3 protein (P>0.05). Large-dose LPS challenge significantly increased the activity of calpain in the liver tissue (P<0.05) to a comparable level in the 3 groups (P>0.05). Endotoxin pretreatment induces inhibitory phosphorylation of GSK-3β and partial cleavage of GSK-3α and promotes the deposition of liver glycogen but does not affect the activity of calpain, which may contribute to an increased glycogen reserve for energy supply in the event of large-dose LPS challenge.

Mangiferin inhibits lipopolysaccharide-induced production of interleukin-6 in human oral epithelial cells by suppressing toll-like receptor signaling.

PubMed

Li, Hao; Wang, Qi; Chen, Xinmin; Ding, Yi; Li, Wei

2016-11-01

Oral epithelial cells have currently been found to play an important role in inflammatory modulation in periodontitis. Mangiferin is a natural glucosylxanthone with anti-inflammatory activity. The aim of this study was to investigate the regulatory effect of mangiferin on lipopolysaccharide (LPS)-induced production of proinflammatory cytokine interleukin-6 (IL-6) in oral epithelial cells and the underlying mechanisms. The levels of LPS-induced IL-6 production in OKF6/TERT-2 oral keratinocytes were detected using enzyme-linked immunosorbent assay (ELISA). The expression of Toll-like receptor (TLR) 2 and TLR4 was determined using western blot analysis. And the phosphorylation of TLR downstream nuclear factor-κB (NF-κB), p38 mitogen-activated protein kinase (p38 MAPK) and c-Jun N-terminal kinase (JNK) was examined using cell-based protein phosphorylation ELISA kits. We found that mangiferin reduced LPS-upregulated IL-6 production in OKF6/TERT-2 cells. Additionally, mangiferin inhibited LPS-induced TLR2 and TLR4 overexpression, and suppressed the phosphorylation of NF-κB, p38 MAPK and JNK. Moreover, mangiferin repressed IL-6 production and TLR signaling activation in a dose-dependent manner after 24h treatment. Mangiferin decreases LPS-induced production of IL-6 in human oral epithelial cells by suppressing TLR signaling, and this glucosylxanthone may have potential for the treatment of periodontitis. Copyright © 2016 Elsevier Ltd. All rights reserved.

Tat-CBR1 inhibits inflammatory responses through the suppressions of NF-κB and MAPK activation in macrophages and TPA-induced ear edema in mice

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Young Nam; Kim, Dae Won; Jo, Hyo Sang

Human carbonyl reductase 1 (CBR1) plays a crucial role in cell survival and protects against oxidative stress response. However, its anti-inflammatory effects are not yet clearly understood. In this study, we examined whether CBR1 protects against inflammatory responses in macrophages and mice using a Tat-CBR1 protein which is able to penetrate into cells. The results revealed that purified Tat-CBR1 protein efficiently transduced into Raw 264.7 cells and inhibited lipopolysaccharide (LPS)-induced cyclooxygenase-2 (COX-2), nitric oxide (NO) and prostaglandin E{sub 2} (PGE{sub 2}) expression levels. In addition, Tat-CBR1 protein leads to decreased pro-inflammatory cytokine expression through suppression of nuclear transcription factor-kappaB (NF-κB)more » and mitogen activated protein kinase (MAPK) activation. Furthermore, Tat-CBR1 protein inhibited inflammatory responses in 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced skin inflammation when applied topically. These findings indicate that Tat-CBR1 protein has anti-inflammatory properties in vitro and in vivo through inhibition of NF-κB and MAPK activation, suggesting that Tat-CBR1 protein may have potential as a therapeutic agent against inflammatory diseases. - Highlights: • Transduced Tat-CBR1 reduces LPS-induced inflammatory mediators and cytokines. • Tat-CBR1 inhibits MAPK and NF-κB activation. • Tat-CBR1 ameliorates inflammation response in vitro and in vivo. • Tat-CBR1 may be useful as potential therapeutic agent for inflammation.« less

IGF-1 attenuates LPS induced pro-inflammatory cytokines expression in buffalo (Bubalus bubalis) granulosa cells.

PubMed

Onnureddy, K; Ravinder; Onteru, Suneel Kumar; Singh, Dheer

2015-03-01

Interaction between immune and endocrine system is a diverse process influencing cellular function and homeostasis in animals. Negative energy balance (NEB) during postpartum period in dairy animals usually suppresses these systems resulting in reproductive tract infection and infertility. These negative effects could be due to competition among endocrine and immune signaling pathways for common signaling molecules. The present work studied the effect of IGF-1 (50 ng/ml) on LPS (1 μg/ml) mediated pro-inflammatory cytokine expression (IL-1β, TNF-α, IL-6) and aromatase (CYP19A1) genes' expressions as well as proliferation of buffalo granulosa cells. The crosstalk between LPS and IGF-1 was also demonstrated through studying the activities of downstream signaling molecules (ERK1/2, Akt, NF-κB) by western blot and immunostaining. Gene expression analysis showed that IGF-1 significantly reduced the LPS induced expression of IL-1β, TNF-α and IL-6. LPS alone inhibited the CYP19A1 expression. However, co-treatment with IGF-1 reversed the inhibitory effect of LPS on CYP19A1 expression. LPS alone did not affect granulosa cell proliferation, but co-treatment with IGF-1, and IGF-1 alone enhanced the proliferation. Western blot results demonstrated that LPS caused the nuclear translocation of the NF-κB and increased the phosphorylation of ERK1/2 and Akt maximum at 15 min and 60 min, respectively. Nonetheless, co-treatment with IGF-1 delayed LPS induced phosphorylation of ERK1/2 (peak at 120 min), while promoting early Akt phosphorylation (peak at 5 min) with no effect on NF-κB translocation. Overall, IGF-1 delayed and reversed the effects of LPS, suggesting that high IGF-1 levels may combat infection during critical periods like NEB in postpartum dairy animals. Copyright © 2014 Elsevier Ltd. All rights reserved.

Therapeutic Effect of Intravenous Infusion of Perfluorocarbon Emulsion on LPS-Induced Acute Lung Injury in Rats

PubMed Central

Lv, Qi; Yin, Xiaofeng; Song, Jianqi; Landén, Ning Xu; Fan, Haojun

2014-01-01

Acute lung injury (ALI) and its more severe form, acute respiratory distress syndrome (ARDS) are the leading causes of death in critical care. Despite extensive efforts in research and clinical medicine, mortality remains high in these diseases. Perfluorocarbon (PFC), a chemical compound known as liquid ventilation medium, is capable of dissolving large amounts of physiologically important gases (mainly oxygen and carbon dioxide). In this study we aimed to investigate the effect of intravenous infusion of PFC emulsion on lipopolysaccharide (LPS) induced ALI in rats and elucidate its mechanism of action. Forty two Wistar rats were randomly divided into three groups: 6 rats were treated with saline solution by intratracheal instillation (control group), 18 rats were treated with LPS by intratracheal instillation (LPS group) and the other 18 rats received PFC through femoral vein prior to LPS instillation (LPS+PFC group). The rats in the control group were sacrificed 6 hours later after saline instillation. At 2, 4 and 6 hours of exposure to LPS, 6 rats in the LPS group and 6 rats in LPS+PFC group were sacrificed at each time point. By analyzing pulmonary pathology, partial pressure of oxygen in the blood (PaO2) and lung wet-dry weight ratio (W/D) of each rat, we found that intravenous infusion of PFC significantly alleviated acute lung injury induced by LPS. Moreover, we showed that the expression of pulmonary myeloperoxidase (MPO), intercellular adhesion molecule-1 (ICAM-1) of endothelial cells and CD11b of polymorphonuclear neutrophils (PMN) induced by LPS were significantly decreased by PFC treatment in vivo. Our results indicate that intravenous infusion of PFC inhibits the infiltration of PMNs into lung tissue, which has been shown as the core pathogenesis of ALI/ARDS. Thus, our study provides a theoretical foundation for using intravenous infusion of PFC to prevent and treat ALI/ARDS in clinical practice. PMID:24489970

β-Glucan from Lentinus edodes inhibits nitric oxide and tumor necrosis factor-α production and phosphorylation of mitogen-activated protein kinases in lipopolysaccharide-stimulated murine RAW 264.7 macrophages.

PubMed

Xu, Xiaojuan; Yasuda, Michiko; Nakamura-Tsuruta, Sachiko; Mizuno, Masashi; Ashida, Hitoshi

2012-01-06

Lentinan (LNT), a β-glucan from the fruiting bodies of Lentinus edodes, is well known to have immunomodulatory activity. NO and TNF-α are associated with many inflammatory diseases. In this study, we investigated the effects of LNT extracted by sonication (LNT-S) on the NO and TNF-α production in LPS-stimulated murine RAW 264.7 macrophages. The results suggested that treatment with LNT-S not only resulted in the striking inhibition of TNF-α and NO production in LPS-activated macrophage RAW 264.7 cells, but also the protein expression of inducible NOS (iNOS) and the gene expression of iNOS mRNA and TNF-α mRNA. It is surprising that LNT-S enhanced LPS-induced NF-κB p65 nuclear translocation and NF-κB luciferase activity, but severely inhibited the phosphorylation of JNK1/2 and ERK1/2. The neutralizing antibodies of anti-Dectin-1 and anti-TLR2 hardly affected the inhibition of NO production. All of these results suggested that the suppression of LPS-induced NO and TNF-α production was at least partially attributable to the inhibition of JNK1/2 and ERK1/2 activation. This work discovered a promising molecule to control the diseases associated with overproduction of NO and TNF-α.

Milk Thistle Extract and Silymarin Inhibit Lipopolysaccharide Induced Lamellar Separation of Hoof Explants in Vitro

PubMed Central

Reisinger, Nicole; Schaumberger, Simone; Nagl, Veronika; Hessenberger, Sabine; Schatzmayr, Gerd

2014-01-01

The pathogenesis of laminitis is not completely identified and the role of endotoxins (lipopolysaccharides, LPS) in this process remains unclear. Phytogenic substances, like milk thistle (MT) and silymarin, are known for their anti-inflammatory and antioxidant properties and might therefore have the potential to counteract endotoxin induced effects on the hoof lamellar tissue. The aim of our study was to investigate the influence of endotoxins on lamellar tissue integrity and to test if MT and silymarin are capable of inhibiting LPS-induced effects in an in vitro/ex vivo model. In preliminary tests, LPS neutralization efficiency of these phytogenics was determined in an in vitro neutralization assay. Furthermore, tissue explants gained from hooves of slaughter horses were tested for lamellar separation after incubation with different concentrations of LPS. By combined incubation of explants with LPS and either Polymyxin B (PMB; positive control), MT or silymarin, the influence of these substances on LPS-induced effects was assessed. In the in vitro neutralization assay, MT and silymarin reduced LPS concentrations by 64% and 75%, respectively, in comparison PMB reduced 98% of the LPS concentration. In hoof explants, LPS led to a concentration dependent separation. Accordantly, separation force was significantly decreased by 10 µg/mL LPS. PMB, MT and silymarin could significantly improve tissue integrity of explants incubated with 10 µg/mL LPS. This study showed that LPS had a negative influence on the structure of hoof explants in vitro. MT and silymarin reduced endotoxin activity and inhibited LPS-induced effects on the lamellar tissue. Hence, MT and silymarin might be used to support the prevention of laminitis and should be further evaluated for this application. PMID:25290524

Milk thistle extract and silymarin inhibit lipopolysaccharide induced lamellar separation of hoof explants in vitro.

PubMed

Reisinger, Nicole; Schaumberger, Simone; Nagl, Veronika; Hessenberger, Sabine; Schatzmayr, Gerd

2014-10-06

The pathogenesis of laminitis is not completely identified and the role of endotoxins (lipopolysaccharides, LPS) in this process remains unclear. Phytogenic substances, like milk thistle (MT) and silymarin, are known for their anti-inflammatory and antioxidant properties and might therefore have the potential to counteract endotoxin induced effects on the hoof lamellar tissue. The aim of our study was to investigate the influence of endotoxins on lamellar tissue integrity and to test if MT and silymarin are capable of inhibiting LPS-induced effects in an in vitro/ex vivo model. In preliminary tests, LPS neutralization efficiency of these phytogenics was determined in an in vitro neutralization assay. Furthermore, tissue explants gained from hooves of slaughter horses were tested for lamellar separation after incubation with different concentrations of LPS. By combined incubation of explants with LPS and either Polymyxin B (PMB; positive control), MT or silymarin, the influence of these substances on LPS-induced effects was assessed. In the in vitro neutralization assay, MT and silymarin reduced LPS concentrations by 64% and 75%, respectively, in comparison PMB reduced 98% of the LPS concentration. In hoof explants, LPS led to a concentration dependent separation. Accordantly, separation force was significantly decreased by 10 µg/mL LPS. PMB, MT and silymarin could significantly improve tissue integrity of explants incubated with 10 µg/mL LPS. This study showed that LPS had a negative influence on the structure of hoof explants in vitro. MT and silymarin reduced endotoxin activity and inhibited LPS-induced effects on the lamellar tissue. Hence, MT and silymarin might be used to support the prevention of laminitis and should be further evaluated for this application.

Discovery of new MD2 inhibitor from chalcone derivatives with anti-inflammatory effects in LPS-induced acute lung injury

PubMed Central

Zhang, Yali; Wu, Jianzhang; Ying, Shilong; Chen, Gaozhi; Wu, Beibei; Xu, Tingting; Liu, Zhiguo; Liu, Xing; Huang, Lehao; Shan, Xiaoou; Dai, Yuanrong; Liang, Guang

2016-01-01

Acute lung injury (ALI) is a life-threatening acute inflammatory disease with limited options available for therapy. Myeloid differentiation protein 2, a co-receptor of TLR4, is absolutely required for TLR4 sense LPS, and represents an attractive target for treating severe inflammatory diseases. In this study, we designed and synthesized 31 chalcone derivatives that contain the moiety of (E)-4-phenylbut-3-en-2-one, which we consider the core structure of current MD2 inhibitors. We first evaluated the anti-inflammatory activities of these compounds in MPMs. For the most active compound 20, we confirmed that it is a specific MD2 inhibitor through a series of biochemical experiments and elucidated that it binds to the hydrophobic pocket of MD2 via hydrogen bonds with Arg90 and Tyr102 residues. Compound 20 also blocked the LPS-induced activation of TLR4/MD2 -downstream pro-inflammatory MAPKs/NF-κB signaling pathways. In a rat model with ALI induced by intracheal LPS instillation, administration with compound 20 exhibited significant protective effect against ALI, accompanied by the inhibition of TLR4/MD2 complex formation in lung tissues. Taken together, the results of this study suggest the specific MD2 inhibitor from chalcone derivatives we identified is a potential candidate for treating acute inflammatory diseases. PMID:27118147

Protection against LPS-induced cartilage inflammation and degradation provided by a biological extract of Mentha spicata

PubMed Central

2010-01-01

Background A variety of mint [Mentha spicata] has been bred which over-expresses Rosmarinic acid (RA) by approximately 20-fold. RA has demonstrated significant anti-inflammatory activity in vitro and in small rodents; thus it was hypothesized that this plant would demonstrate significant anti-inflammatory activity in vitro. The objectives of this study were: a) to develop an in vitro extraction procedure which mimics digestion and hepatic metabolism, b) to compare anti-inflammatory properties of High-Rosmarinic-Acid Mentha spicata (HRAM) with wild-type control M. spicata (CM), and c) to quantify the relative contributions of RA and three of its hepatic metabolites [ferulic acid (FA), caffeic acid (CA), coumaric acid (CO)] to anti-inflammatory activity of HRAM. Methods HRAM and CM were incubated in simulated gastric and intestinal fluid, liver microsomes (from male rat) and NADPH. Concentrations of RA, CA, CO, and FA in simulated digest of HRAM (HRAMsim) and CM (CMsim) were determined (HPLC) and compared with concentrations in aqueous extracts of HRAM and CM. Cartilage explants (porcine) were cultured with LPS (0 or 3 μg/mL) and test article [HRAMsim (0, 8, 40, 80, 240, or 400 μg/mL), or CMsim (0, 1, 5 or 10 mg/mL), or RA (0.640 μg/mL), or CA (0.384 μg/mL), or CO (0.057 μg/mL) or FA (0.038 μg/mL)] for 96 h. Media samples were analyzed for prostaglandin E2 (PGE2), interleukin 1β (IL-1), glycosaminoglycan (GAG), nitric oxide (NO) and cell viability (differential live-dead cell staining). Results RA concentration of HRAMsim and CMsim was 49.3 and 0.4 μg/mL, respectively. CA, FA and CO were identified in HRAMsim but not in aqueous extract of HRAM. HRAMsim (≥ 8 μg/mL) inhibited LPS-induced PGE2 and NO; HRAMsim (≥ 80 μg/mL) inhibited LPS-induced GAG release. RA inhibited LPS-induced GAG release. No anti-inflammatory or chondroprotective effects of RA metabolites on cartilage explants were identified. Conclusions Our biological extraction procedure produces a

Cyanidin-3-O-β-glucoside inhibits lipopolysaccharide-induced inflammatory response in mouse mastitis model

PubMed Central

Fu, Yunhe; Wei, Zhengkai; Zhou, Ershun; Zhang, Naisheng; Yang, Zhengtao

2014-01-01

Cyanidin-3-O-β-glucoside (C3G) (CAS number 7084-24-4), a typical anthocyanin pigment that exists in the human diet, has been reported to have anti-inflammatory properties. However, the effect of C3G on lipopolysaccharide (LPS)-induced mastitis and the molecular mechanisms have not been investigated. In this study, we detected the protective effects of C3G on a LPS-induced mouse mastitis model and investigated the molecular mechanisms in LPS-stimulated mouse mammary epithelial cells (MMECs). Our results showed that C3G could attenuate mammary histopathologic changes and myeloperoxidase activity, and inhibit TNF-α, interleukin (IL)-1β, and IL-6 production caused by LPS. Meanwhile, C3G dose-dependently inhibited TNF-α and IL-6 in LPS-stimulated MMECs. C3G suppressed LPS-induced nuclear factor-κB (NF-κB) and interferon regulatory factor 3 (IRF3) activation. Furthermore, C3G disrupted the formation of lipid rafts by depleting cholesterol. Moreover, C3G activated liver X receptor (LXR)-ABCG1-dependent cholesterol efflux. Knockdown of LXRα abrogated the anti-inflammatory effects of C3G. In conclusion, C3G has a protective effect on LPS-induced mastitis. The promising anti-inflammatory mechanisms of C3G are associated with upregulation of the LXRα-ABCG1 pathway which result in disrupting lipid rafts by depleting cholesterol, thereby suppressing toll-like receptor 4-mediated NF-κB and IRF3 signaling pathways induced by LPS. PMID:24752550

Rosmanol potently inhibits lipopolysaccharide-induced iNOS and COX-2 expression through downregulating MAPK, NF-kappaB, STAT3 and C/EBP signaling pathways.

PubMed

Lai, Ching-Shu; Lee, Jong Hun; Ho, Chi-Tang; Liu, Cheng Bin; Wang, Ju-Ming; Wang, Ying-Jan; Pan, Min-Hsiung

2009-11-25

Rosmanol is a natural polyphenol from the herb rosemary (Rosmarinus officinalis L.) with high antioxidant activity. In this study, we investigated the inhibitory effects of rosmanol on the induction of NO synthase (NOS) and COX-2 in RAW 264.7 cells induced by lipopolysaccharide (LPS). Rosmanol markedly inhibited LPS-stimulated iNOS and COX-2 protein and gene expression, as well as the downstream products, NO and PGE2. Treatment with rosmanol also reduced translocation of the nuclear factor-kappaB (NF-kappaB) subunits by prevention of the degradation and phosphorylation of inhibitor kappaB (IkappaB). Western blot analysis showed that rosmanol significantly inhibited translocation and phosphorylation of NF-kappaB, signal transducer and activator of transcription-3 (STAT3), and the protein expression of C/EBPbeta and C/EBPdelta. We also found that rosmanol suppressed LPS-induced phosphorylation of ERK1/2, p38 mitogen-activated protein kinase (MAPK) and phosphatidylinositol 3-kinase (PI3K)/Akt signaling. Our results demonstrate that rosmanol downregulates inflammatory iNOS and COX-2 gene expression by inhibiting the activation of NF-kappaB and STAT3 through interfering with the activation of PI3K/Akt and MAPK signaling. Taken together, rosmanol might contribute to the potent anti-inflammatory effect of rosemary and may have potential to be developed into an effective anti-inflammatory agent.

Anti-inflammatory effect of a standardized triterpenoid-rich fraction isolated from Rubus coreanus on dextran sodium sulfate-induced acute colitis in mice and LPS-induced macrophages.

PubMed

Shin, Ji-Sun; Cho, Eu-Jin; Choi, Hye-Eun; Seo, Ji-Hyung; An, Hyo-Jin; Park, Hee-Juhn; Cho, Young-Wuk; Lee, Kyung-Tae

2014-12-02

Rubus coreanus Miquel (Rosaceae), the Korean black raspberry, has traditionally been used to treat inflammatory diseases including diarrhea, asthma, stomach ailment, and cancer. Although previous studies showed that the 19α-hydroxyursane-type triterpenoids isolated from Rubus coreanus exerted anti-inflammatory activities, their effects on ulcerative colitis and mode of action have not been explored. This study was designed to assess the anti-inflammatory effects and the molecular mechanisms involving19α-hydroxyursane-type triterpenoid-rich fraction from Rubus coreanus (TFRC) on a mice model of colitis and lipopolysaccharide (LPS)-induced RAW 264.7 macrophages. Experimental colitis was induced by DSS for 7 days in ICR mice. Disease activity indices (DAI) took into account body weight, stool consistency, and gross bleeding. Histological changes and macrophage accumulation were observed by immunohistochemical analysis. Pro-inflammatory markers were determined using immunoassays, RT-PCR, and real time PCR. Signaling pathway involving nuclear factor-κB (NF-κB) and mitogen-activated protein kinases (MAPKs) activation was determined by luciferase assay and Western blotting. In DSS-induced colitis mice, TFRC improved DAIs and pathological characteristics including colon shortening and colonic epithelium injury. TFRC suppressed tissue levels of pro-inflammatory cytokines and reduced macrophage infiltration into colonic tissues. In LPS-induced RAW 264.7 macrophages, TFRC inhibited the production of NO, PGE2, and pro-inflammatory cytokines by down-regulating the activation of NF-κB and p38 MAPK signaling. The study demonstrates that TFRC has potent anti-inflammatory effects on DSS-induced colonic injury and LPS-induced macrophage activation, and supports its possible therapeutic and preventive roles in colitis. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Uncaria rhynchophylla inhibits the production of nitric oxide and interleukin-1β through blocking nuclear factor κB, Akt, and mitogen-activated protein kinase activation in macrophages.

PubMed

Kim, Ji-Hee; Bae, Chang Hwan; Park, Sun Young; Lee, Sang Joon; Kim, YoungHee

2010-10-01

The stems with hook of Uncaria rhynchophylla have been used in traditional medicine as an antipyretic, antihypertensive, and anticonvulsant in China and Korea. In this study, we investigated the mechanism responsible for anti-inflammatory effects of U. rhynchophylla in RAW 264.7 macrophages. The aqueous extract of U. rhynchophylla inhibited lipopolysaccharide (LPS)-induced nitric oxide (NO) and interleukin (IL)-1β secretion as well as inducible NO synthase (iNOS) expression, without affecting cell viability. Furthermore, U. rhynchophylla suppressed LPS-induced nuclear factor κB (NF-κB) activation, phosphorylation, and degradation of inhibitory protein IκB (IκB)-α, phosphorylation of Akt, extracellular signal-regulated kinase 1/2, p38 kinase, and c-Jun N-terminal kinase. These results suggest that U. rhynchophylla has the inhibitory effects on LPS-induced NO and IL-1β production in macrophages through blockade in the phosphorylation of Akt and mitogen-activated protein kinases, following IκB-α degradation and NF-κB activation.

XOR inhibition with febuxostat accelerates pulmonary endothelial barrier recovery and improves survival in lipopolysaccharide-induced murine sepsis.

PubMed

Damarla, Mahendra; Johnston, Laura F; Liu, Gigi; Gao, Li; Wang, Lan; Varela, Lidenys; Kolb, Todd M; Kim, Bo S; Damico, Rachel L; Hassoun, Paul M

2017-08-01

Sepsis is a leading cause of death among patients in the intensive care unit, resulting from multi-organ failure. Activity of xanthine oxidoreductase (XOR), a reactive oxygen species (ROS) producing enzyme, is known to be elevated in nonsurvivors of sepsis compared to survivors. We have previously demonstrated that XOR is critical for ventilator-induced lung injury. Using febuxostat, a novel nonpurine inhibitor of XOR, we sought to determine the role of XOR inhibition in a murine model of sepsis-induced lung injury and mortality. C57BL/6J mice were subjected to intravenous (IV) lipopolysaccharide (LPS) for various time points, and lungs were harvested for analyses. Subsets of mice were treated with febuxostat, pre or post LPS exposure, or vehicle. Separate groups of mice were followed up for mortality after LPS exposure. After 24 hr of IV LPS , mice exhibited an increase in XOR activity in lung tissue and a significant increase in pulmonary endothelial barrier disruption. Pretreatment of animals with febuxostat before exposure to LPS, or treatment 4 h after LPS, resulted in complete abrogation of XOR activity. Inhibition of XOR with febuxostat did not prevent LPS-induced pulmonary vascular permeability at 24 h, however, it accelerated recovery of the pulmonary endothelial barrier integrity in response to LPS exposure. Furthermore, treatment with febuxostat resulted in significant reduction in mortality. Inhibition of XOR with febuxostat accelerates recovery of the pulmonary endothelial barrier and prevents LPS-induced mortality, whether given before or after exposure to LPS. © 2017 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American Physiological Society.

[Chrysin inhibits lipopolysaccharide-induced inflammatory responses of macrophages via JAK-STATs signaling pathway].

PubMed

Qi, Shi-Mei; Li, Qiang; Jiang, Qi; Qi, Zhi-Lin; Zhang, Yao

2018-03-20

To investigate the mechanism of chrysin in regulating lipopolysaccharide (LPS)-induced inflammation in RAW264.7 cells. RAW264.7 cells were treated with different concentrations (0, 5, 10, 20, 40, 60, 80, 100, 150, and 200 µg/mL) of chrysin for 24 h, and the cell viability was measured using CCK-8. RAW264.7 cells were pre-treated with 10, 30, or 60 µg/mL chrysin for 2 h before stimulation with LPS for different times. The levels of TNF-α, IL-6 and MCP-1 were detected by ELISA, and Western blotting was used to detect the phosphorylation of JAK- 1, JAK-2, STAT-1 and STAT-3. The level of reactive oxygen species in RAW264.7 cells was detected by CM-H2DCFDA fluorescence probe. The effect of ROS on LPS-induced JAK-STATs signal and the inflammatory response of RAW264.7 cells was detected by ROS scavenger NAC. The transcription factors STAT-1 and STAT-3 nuclear translocation were observed by laser confocal microscopy. Chrysin below 60 µg/mL did not significantly affect the viability of RAW264.7 cells. At 10, 30, and 60 µg/mL, chrysin dose-dependently inhibited the expression of iNOS induced by LPS. Chrysin treatment also inhibited LPS-induced phosphorylation of JAK-STATs, nuclear translocation of STAT1 and STAT3, release of TNF-α, IL-6 and MCP-1, and the production of ROS in RAW264.7 cells; ROS acted as an upstream signal to mediate the activation of JAK-STATs signaling pathway. Chrysin blocks the activity of JAK-STATs mediated by ROS to inhibit LPS-induced inflammatory response in RAW264.7 cells.

Noradrenaline inhibits lipopolysaccharide-induced tumor necrosis factor and interleukin 6 production in human whole blood.

PubMed Central

van der Poll, T; Jansen, J; Endert, E; Sauerwein, H P; van Deventer, S J

1994-01-01

Sepsis and lipopolysaccharide (LPS) trigger the systemic release of both cytokines and catecholamines. Cytokines are known to be capable of eliciting a stress hormone response in vivo. The present study sought insight into the effect of noradrenaline on LPS-induced release of tumor necrosis factor alpha (TNF) and interleukin 6 (IL-6) in human whole blood. Whole blood was incubated with LPS for 4 h at 37 degrees C in the presence and absence of noradrenaline and/or specific alpha and beta antagonists and agonists. Noradrenaline caused a dose-dependent inhibition of LPS-induced TNF and IL-6 production. This effect could be completely prevented by addition of the specific beta 1, antagonist metoprolol, while it was not affected by the alpha antagonist phentolamine. Specific beta-adrenergic stimulation by isoprenaline mimicked the inhibiting effect of noradrenaline on LPS-evoked cytokine production, whereas alpha-adrenergic stimulation by phenylephrine had no effect. Fluorescence-activated cell sorter analysis demonstrated that beta-adrenergic stimulation had no effect on LPS binding to and internalization into mononuclear cells or on the expression of CD14, the major receptor for LPS on mononuclear cells. In acute sepsis, enhanced release of noradrenaline may be part of a negative feedback mechanism meant to inhibit ongoing TNF and IL-6 production. PMID:8168970

Esculin attenuates endotoxin shock induced by lipopolysaccharide in mouse and NO production in vitro through inhibition of NF-κB activation.

PubMed

Li, Weifeng; Wang, Yu; Wang, Xiumei; He, Zehong; Liu, Fang; Zhi, Wenbing; Zhang, Hailin; Niu, Xiaofeng

2016-11-15

Esculin, a coumarin compound derived from the traditional Chinese herbs such as Cortex Fraxini, has long been used for treating inflammatory and vascular diseases. In present study, we analyzed the role of esculin against macrophages and endotoxin shock induced by lipopolysaccharide (LPS) in mice. Here, we demonstrated that esculin suppressed inflammatory reactions in macrophages and protected mice from LPS-induced endotoxin shock. We found that esculin significantly inhibited the production of nitric oxide (NO) production via the inhibition of nuclear factor-κB (NF-κB) activation in macrophages. In animal model, esculin pretreatment significantly improved the survival rate of mice. LPS-induced increase of tumor necrosis factor alpha (TNF-α) and interleukin-6 (IL-6) in serum, lung, liver and kidney were markedly inhibited by esculin. IL-10, an anti-inflammatory cytokine, was up-regulated by esculin. Moreover, the histopathological analyses showed that esculin significantly attenuated the tissues injury of lung, liver, kidney in endotoxic mice. In addition, esculin significantly diminished the protein expression of NF-κB p65 in lung, liver, kidney, which resulted in lower levels of inflammatory mediators. These results suggest that esculin may be a potential drug for treatment of various inflammatory diseases. Copyright © 2016 Elsevier B.V. All rights reserved.

Flavonoids inhibit cytokine-induced endothelial cell adhesion protein gene expression.

PubMed Central

Gerritsen, M. E.; Carley, W. W.; Ranges, G. E.; Shen, C. P.; Phan, S. A.; Ligon, G. F.; Perry, C. A.

1995-01-01

Treatment of human endothelial cells with cytokines such as interleukin-1, tumor necrosis factor-alpha (TNF-alpha) or interferon-gamma induces the expression of specific leukocyte adhesion molecules on the endothelial cell surface. Interfering with either leukocyte adhesion or adhesion protein upregulation is an important therapeutic target as evidenced by the potent anti-inflammatory actions of neutralizing antibodies to these ligands in various animal models and in patients. In the present study we report that cotreatment of human endothelial cells with certain hydroxyflavones and flavanols blocks cytokine-induced ICAM-1, VCAM-1, and E-selectin expression on human endothelial cells. One of the most potent flavones, apigenin, exhibited a dose- and time-dependent, reversible effect on adhesion protein expression as well as inhibiting adhesion protein upregulation at the transcriptional level. Apigenin also inhibited IL-1 alpha-induced prostaglandin synthesis and TNF-alpha-induced IL-6 and IL-8 production, suggesting that the hydroxyflavones may act as general inhibitors of cytokine-induced gene expression. Although apigenin did not inhibit TNF-alpha-induced nuclear translocation of NF-kappa B(p50(NFKB1)/p65(RelA)) we found this flavonoid did inhibit TNF-alpha induced beta-galactosidase activity in SW480 cells stably transfected with a beta-galactosidase reporter construct driven by four NF-kappa B elements, suggesting an action on NF-kappa B transcriptional activation. Adhesion of leukocytes to cytokine-treated endothelial cells was blocked in endothelial cells cotreated with apigenin. Finally, apigenin demonstrated potent anti-inflammatory activity in carrageenan induced rat paw edema and delayed type hypersensitivity in the mouse. We conclude that flavonoids offer important therapeutic potential for the treatment of a variety of inflammatory diseases involving an increase in leukocyte adhesion and trafficking. Images Figure 7 Figure 8 Figure 11 PMID:7543732

Pseudomonas aeruginosa lipopolysaccharide induces CF-like alteration of protein secretion by human tracheal gland cells.

PubMed

Kammouni, W; Figarella, C; Baeza, N; Marchand, S; Merten, M D

1997-12-18

Human tracheal gland (HTG) serous cells are now believed to play a major role in the physiopathology of cystic fibrosis. Because of the persistent inflammation and the specific infection by Pseudomonas aeruginosa in the lung, we looked for the action of the lipopolysaccharide (LPS) of this bacteria on human tracheal gland cells in culture by studying the secretion of the secretory leukocyte proteinase inhibitor (SLPI) which is a specific serous secretory marker of these cells. Treatment with Pseudomonas aeruginosa LPS resulted in a significant dose-dependent increase in the basal production of SLPI (+ 250 +/- 25%) whilst the SLPI transcript mRNA levels remained unchanged. This LPS-induced increase in secretion was inhibited by glucocorticoides. Furthermore, LPS treatment of HTG cells induces a loss of responsiveness to carbachol and isoproterenol but not to adenosine triphosphate. These findings indicate that HTG cells treated by Pseudomonas aeruginosa LPS have the same behavior as those previously observed with CF-HTG cells. Exploration by using reverse transcriptase polymerase chain reaction amplification showed that LPS downregulated cystic fibrosis transmembrane conductance regulator (CFTR) mRNA expression in HTG cells indicative of a link between CFTR function and consequent CF-like alteration in protein secretory process.

MD-2 as the target of a novel small molecule, L6H21, in the attenuation of LPS-induced inflammatory response and sepsis

PubMed Central

Wang, Yi; Shan, Xiaoou; Chen, Gaozhi; Jiang, Lili; Wang, Zhe; Fang, Qilu; Liu, Xing; Wang, Jingying; Zhang, Yali; Wu, Wencan; Liang, Guang

2015-01-01

Background and Purpose Myeloid differentiation 2 (MD-2) recognizes LPS, which is required for TLR4 activation, and represents an attractive therapeutic target for severe inflammatory disorders. We previously found that a chalcone derivative, L6H21, could inhibit LPS-induced overexpression of TNF-α and IL-6 in macrophages. Here, we performed a series of biochemical experiments to investigate whether L6H21 specifically targets MD-2 and inhibits the interaction and signalling transduction of LPS-TLR4/MD-2. Experimental Approach The binding affinity of L6H21 to MD-2 protein was analysed using computer docking, surface plasmon resonance analysis, elisa, fluorescence measurements and flow cytometric analysis. The effects of L6H21 on MAPK and NF-κB signalling were determined using EMSA, fluorescence staining, Western blotting and immunoprecipitation. The anti-inflammatory effects of L6H21 were confirmed using elisa and RT-qPCR in vitro. The anti-inflammatory effects of L6H21 were also evaluated in septic C57BL/6 mice. Key Results Compound L6H21 inserted into the hydrophobic region of the MD-2 pocket, forming hydrogen bonds with Arg90 and Tyr102 in the MD-2 pocket. In vitro, L6H21 subsequently suppressed MAPK phosphorylation, NF-κB activation and cytokine expression in macrophages stimulated by LPS. In vivo, L6H21 pretreatment improved survival, prevented lung injury, decreased serum and hepatic cytokine levels in mice subjected to LPS. In addition, mice with MD-2 gene knockout were universally protected from the effects of LPS-induced septic shock. Conclusions and Implications Overall, this work demonstrated that the new chalcone derivative, L6H21, is a potential candidate for the treatment of sepsis. More importantly, the data confirmed that MD-2 is an important therapeutic target for inflammatory disorders. PMID:26076332

High-throughput living cell-based optical biosensor for detection of bacterial lipopolysaccharide (LPS) using a red fluorescent protein reporter system.

PubMed

Jiang, Hui; Jiang, Donglei; Shao, Jingdong; Sun, Xiulan; Wang, Jiasheng

2016-11-14

Due to the high toxicity of bacterial lipopolysaccharide (LPS), resulting in sepsis and septic shock, two major causes of death worldwide, significant effort is directed toward the development of specific trace-level LPS detection systems. Here, we report sensitive, user-friendly, high-throughput LPS detection in a 96-well microplate using a transcriptional biosensor system, based on 293/hTLR4A-MD2-CD14 cells that are transformed by a red fluorescent protein (mCherry) gene under the transcriptional control of an NF-κB response element. The recognition of LPS activates the biosensor cell, TLR4, and the co-receptor-induced NF-κB signaling pathway, which results in the expression of mCherry fluorescent protein. The novel cell-based biosensor detects LPS with specificity at low concentration. The cell-based biosensor was evaluated by testing LPS isolated from 14 bacteria. Of the tested bacteria, 13 isolated Enterobacteraceous LPSs with hexa-acylated structures were found to increase red fluorescence and one penta-acylated LPS from Pseudomonadaceae appeared less potent. The proposed biosensor has potential for use in the LPS detection in foodstuff and biological products, as well as bacteria identification, assisting the control of foodborne diseases.

Inhibition of inducible nitric oxide synthase expression by novel nonsteroidal anti-inflammatory derivatives with gastrointestinal-sparing properties.

PubMed Central

Cirino, G.; Wheeler-Jones, C. P.; Wallace, J. L.; Del Soldato, P.; Baydoun, A. R.

1996-01-01

1. The effects of novel nitric oxide-releasing nonsteroidal anti-inflammatory compounds (NO-NSAIDs) on induction of nitric oxide (NO) synthase by bacterial lipopolysaccharide (LPS) were examined in a murine cultured macrophage cell line, J774. 2. LPS-induced nitrite production was markedly attenuated by the nitroxybutylester derivatives of flurbiprofen (FNBE), aspirin, ketoprofen, naproxen, diclofenac and ketorolac, with each compound reducing accumulated nitrite levels by > 40% at the maximum concentrations (100 micrograms ml-1) used. 3. Further examination revealed that nitrite production was inhibited in a concentration-dependent (1-100 micrograms ml-1) manner by FNBE which at 100 micrograms ml-1 decreased LPS-stimulated levels by 63.3 +/- 8.6% (n = 7). The parent compound flurbiprofen was relatively ineffective over the same concentration-range, inhibiting nitrite accumulation by 24 +/- 0.9% (n = 3) at the maximum concentration used (100 micrograms ml-1). 4. FNBE reduced LPS-induced nitrite production when added to cells up to 4 h after LPS. Thereafter, FNBE caused very little or no reduction in nitrite levels. Furthermore NO-NSAIDs (100 micrograms ml-1) did not inhibit the metabolism of L-[3H]-arginine to citrulline by NO synthase isolated from LPS-activated macrophages. 5. Western blot analysis demonstrated that NO synthase expression was markedly attenuated following co-incubation of J774 cell with LPS (1 microgram ml-1; 24 h) and FNBE (100 micrograms ml-1; 24 h). Thus taken together, these findings indicate that NO-NSAIDs inhibit induction of NO synthase without directly affecting enzyme activity. 6. In conclusion our results indicate that NO-NSAIDs can inhibit the inducible L-arginine-NO pathway, and are capable of suppressing NO synthesis by inhibiting expression of NO synthase. The clinical implications of these findings remain to be established. Images Figure 4 PMID:8730734

Regulation of endotoxin-induced inhibition of macrophage migration by fresh serum.

PubMed Central

Heilman, D H

1977-01-01

Purified endotoxin (LPS) caused macrophage migration inhibition (MMI) in capillary tube cultures of guinea pig peritoneal macrophages in medium prepared with 15% fresh-frozen guinea pig serum. The inactivation of serum by heating at 56 degrees C for 30 min or by zymosan absorption prevented LPS-induced MMI. LPS was fully inhibitory in fresh C4-deficient guinea pig serum. Heat treatment of normal serum at 50 to 52 degrees C for 30 min to inactivate the alternate complement (C) pathway prevented or significantly decreased LPS-induced MMI, but heating C4-deficient serum at 50 to 52 degrees C for 30 min prevented LPS-MMI in all instances. These results suggest that the reaction was effected via the alternate C pathway but that some inhibition of migration was permitted via the classical C pathway, presumably due to antibodies for LPS in some normal sera. Pretreatment of normal serum with cobra venom factor decreased or prevented LPS-MMI in most instances, but similar results were obtained with C4-deficient serum. Experiments with chelated sera were unsuccessful because of the immobilization of macrophages by 10 mM ethylenediamine-tetraacetic acid and by 10 mM Mg-ethyleneglycol-bis (beta-aminoethyl)-N,N-tetraacetic acid. Low doses of concanavalin A and staphylococcal enterotoxin B and large doses of pokeweed mitogen caused MMI in "inactivated serum" medium, but MMI was enhanced in fresh serum. PMID:330407

Polygonum viviparum L. inhibits the lipopolysaccharide-induced inflammatory response in RAW264.7 macrophages through haem oxygenase-1 induction and activation of the Nrf2 pathway.

PubMed

Cheng, Hui-Wen; Lee, Kock-Chee; Cheah, Khoot-Peng; Chang, Ming-Long; Lin, Che-Wei; Li, Joe-Sharg; Yu, Wen-Yu; Liu, E-Tung; Hu, Chien-Ming

2013-02-01

Polygonum viviparum L. (PV) is a member of the family Polygonaceae and is widely distributed in high-elevation areas. It is used as a folk remedy to treat inflammation-related diseases. This study was focused on the anti-inflammatory response of PV against lipopolysaccharide (LPS)-induced inflammation in RAW264.7 macrophages. Treatment with PV did not cause cytotoxicity at 0-50 µg mL(-1) in RAW264.7 macrophages, and the IC(50) value was 270 µg mL(-1). PV inhibited LPS-stimulated nitric oxide (NO), prostaglandin (PG)E(2) , interleukin (IL)-1β and tumour necrosis factor (TNF)-α release and inducible NO synthase (iNOS) and cyclooxygenase (COX)-2 protein expression. In addition, PV suppressed the LPS-induced p65 expression of nuclear factor (NF)-κB, which is associated with the inhibition of IκB-α degradation. These results suggest that, among mechanisms of the anti-inflammatory response, PV inhibits the production of NO and these cytokines by down-regulating iNOS and COX-2 gene expression. Furthermore, PV can induce haem oxygenase (HO)-1 protein expression through nuclear factor E2-related factor 2 (Nrf2) activation. A specific inhibitor of HO-1, zinc(II) protoporphyrin IX, inhibited the suppression of iNOS and COX-2 expression by PV. These results suggest that PV possesses anti-inflammatory actions in macrophages and works through a novel mechanism involving Nrf2 actions and HO-1. Thus PV could be considered for application as a potential therapeutic approach for inflammation-associated disorders. Copyright © 2012 Society of Chemical Industry.

Pharmacological modulation of lipopolysaccharide-induced pleural eosinophilia in the rat; a role for a newly generated protein.

PubMed

Bozza, P T; Castro-Faria-Neto, H C; Martins, M A; Larangeira, A P; Perales, J E; e Silva, P M; Cordeiro, R S

1993-06-01

Intrathoracic injection of endotoxin lipopolysaccharide, LPS into rats induced a dose-dependent increase in the number of eosinophils recovered from the pleural cavity. The pleural eosinophil accumulation peaked within 24-48 h, and returned to basal levels within 120 h. This phenomenon was accompanied by mononuclear cell infiltration, and preceded by massive neutrophil accumulation. Pretreatment with indomethacin, BW 755C (a dual cyclo/lipoxygenase inhibitor), BW A4C (a specific lipoxygenase inhibitor) or the platelet activating factor (PAF) antagonists WEB 2086 and PCA 4248 failed to inhibit the endotoxin-induced pleural eosinophilia, whilst dexamethasone (5-10 micrograms/cavity) or cycloheximide (14-28 micrograms/cavity) abolished this phenomenon. Transfer of the cell-free pleural washing from LPS-treated donor rats to normal recipient rats led to a two-fold increase in the eosinophil counts. Treatment of donors, but not recipients, with cycloheximide or dexamethasone inhibited the eosinophil accumulation induced by the pleural washings, indicating that the generation of the eosinophilotactic activity, but not its effects, depends on protein synthesis. This eosinophilotactic activity was maintained after lyophilization and heating (100 degrees C for 30 min), but was destroyed by trypsin. This substance has a molecular weight ranging between 10 and 50 kDa. The available data suggest that the late eosinophil accumulation induced by LPS is independent of arachidonic acid metabolites and PAF, and probably depends on a newly generated heat-stable soluble protein.

Eukaryotic elongation factor 2 controls TNF-α translation in LPS-induced hepatitis

PubMed Central

González-Terán, Bárbara; Cortés, José R.; Manieri, Elisa; Matesanz, Nuria; Verdugo, ρngeles; Rodríguez, María E.; González-Rodríguez, ρgueda; Valverde, ρngela; Martín, Pilar; Davis, Roger J.; Sabio, Guadalupe

2012-01-01

Bacterial LPS (endotoxin) has been implicated in the pathogenesis of acute liver disease through its induction of the proinflammatory cytokine TNF-α. TNF-α is a key determinant of the outcome in a well-established mouse model of acute liver failure during septic shock. One possible mechanism for regulating TNF-α expression is through the control of protein elongation during translation, which would allow rapid cell adaptation to physiological changes. However, the regulation of translational elongation is poorly understood. We found that expression of p38γ/δ MAPK proteins is required for the elongation of nascent TNF-α protein in macrophages. The MKK3/6-p38γ/δ pathway mediated an inhibitory phosphorylation of eukaryotic elongation factor 2 (eEF2) kinase, which in turn promoted eEF2 activation (dephosphorylation) and subsequent TNF-α elongation. These results identify a new signaling pathway that regulates TNF-α production in LPS-induced liver damage and suggest potential cell-specific therapeutic targets for liver diseases in which TNF-α production is involved. PMID:23202732

Somatostatin inhibits cholecystokinin-induced pancreatic protein secretion via cholinergic pathways.

PubMed

Brodish, R J; Kuvshinoff, B W; McFadden, D W; Fink, A S

1995-05-01

Although somatostatin is a potent inhibitor of pancreatic exocrine secretion in vivo, its mechanism of action remains unclear. The influence of extrapancreatic nerves and intrapancreatic cholinergic activity on somatostatin-induced inhibition of pancreatic exocrine secretion was studied in conscious dogs. Chronic pancreatic fistulae were created in six mongrel dogs, and a second group of six dogs also underwent complete pancreatic denervation. The pancreatic responses to graded doses of cholecystokinin (12.5-200 ng/kg/h) and bethanechol (57-916 micrograms/kg/h), both alone and during background infusion of somatostatin-14 (800 pm/kg/h), were determined in all dogs. The cholecystokinin dose-response with a somatostatin-14 background was then repeated with the addition of atropine (10 micrograms/kg/h). In both groups of animals, cholecystokinin elicited a dose-dependent increase in pancreatic protein secretion that was inhibited significantly by somatostatin-14. Regardless of the status of extrapancreatic nerves, atropine further inhibited cholecystokinin-induced protein secretion beyond that evoked by somatostatin-14. In both innervated and denervated animals, cholinergic stimulation with bethanechol elicited a dose-dependent increase in pancreatic protein secretion that was unaffected by somatostatin-14. We conclude that extrapancreatic nerves do not mediate the inhibitory effects of somatostatin-14. Somatostatin-14 appears to inhibit cholecystokinin-induced pancreatic secretion by an intrapancreatic cholinergic mechanism.

Phloretin attenuates LPS-induced acute lung injury in mice via modulation of the NF-κB and MAPK pathways.

PubMed

Huang, Wen-Chung; Lai, Ching-Long; Liang, Yuan-Ting; Hung, Hui-Chih; Liu, Hui-Chia; Liou, Chian-Jiun

2016-11-01

Phloretin, which can be isolated from apple trees, has demonstrable anti-inflammatory and anti-oxidant effects in macrophages. We previously reported that phloretin could inhibit the inflammatory response and reduce intercellular adhesion molecule 1 (ICAM-1) expression in interleukin (IL)-1β-activated human lung epithelial cells. In the present study we now evaluate whether phloretin exposure could ameliorate lipopolysaccharide (LPS)-induced acute lung injury in mice. Intra-peritoneal injections of phloretin were administered to mice for 7 consecutive days, prior to the induction of lung injury by intra-tracheal administration of LPS. Our subsequent analyses demonstrated that phloretin could significantly suppress LPS-induced neutrophil infiltration of lung tissue, and reduce the levels of IL-6 and tumor necrosis factor (TNF)-α in serum and bronchoalveolar lavage fluid. We also found that phloretin modulated myeloperoxidase activity and superoxide dismutase activity, with decreased gene expression levels for chemokines, proinflammatory cytokines, and ICAM-1 in inflamed lung tissue. Phloretin also significantly reduced the phosphorylation of nuclear factor kappa B (NF-κB) and mitogen-activated protein kinase (MAPK), thus limiting the inflammatory response, while promoting expression of heme oxygenase (HO)-1 and nuclear factor erythroid 2-related factor 2, both of which are cytoprotective. Our findings suggest that, mechanistically, phloretin attenuates the inflammatory and oxidative stress pathways that accompany lung injury in mice via blockade of the NF-κB and MAPK pathways. Copyright © 2016. Published by Elsevier B.V.

Indirubin-3′-(2,3 dihydroxypropyl)-oximether (E804) is a potent modulator of LPS-stimulated macrophage functions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Babcock, Abigail S.; Anderson, Amy L.; Graduate Program in Environmental Toxicology, Clemson University, Clemson, SC 29634

2013-01-01

Indirubin is a deep-red bis-indole isomer of indigo blue, both of which are biologically active ingredients in Danggui Longhui Wan, an ancient Chinese herbal tea mixture used to treat neoplasia and chronic inflammation and to enhance detoxification of xenobiotics. Multiple indirubin derivatives have been synthesized and shown to inhibit cyclin-dependent kinases (CDKs) and glycogen-synthase kinase (GSK-3β) with varying degrees of potency. Several indirubins are also aryl hydrocarbon receptor (AhR) agonists, with AhR-associated activities covering a wide range of potencies, depending on molecular structure. This study examined the effects of indirubin-3′-(2,3 dihydroxypropyl)-oximether (E804), a novel indirubin with potent STAT3 inhibitory properties,more » on basal and LPS-inducible activities in murine RAW264.7 macrophages. Using a focused commercial qRT-PCR array platform (SuperArray®), the effects of E804 on expression of a suite of genes associated with stress and toxicity were determined. Most genes up-regulated by LPS treatment were suppressed by E804; including LPS-induced expression of pro-inflammatory cytokines and receptors, apoptosis control genes, and oxidative stress response genes. Using qRT-PCR as a follow up to the commercial arrays, E804 treatment suppressed LPS-induced COX-2, iNOS, IL-6 and IL-10 gene expression, though the effects on iNOS and COX-2 protein expression were less dramatic. E804 also inhibited LPS-induced secretion of IL-6 and IL-10. Functional endpoints, including iNOS and lysozyme enzymatic activity, phagocytosis of fluorescent latex beads, and intracellular killing of bacteria, were also examined, and in each experimental condition E804 suppressed activities. Collectively, these results indicate that E804 is a potent modulator of pro-inflammatory profiles in LPS-treated macrophages. -- Highlights: ► RAW 264.7 macrophages were treated with 1 μM Indirubin E804, 1 μg/ml LPS, or both. ► E804 suppresses LPS-induced

Corydalis bungeana Turcz. attenuates LPS-induced inflammatory responses via the suppression of NF-κB signaling pathway in vitro and in vivo.

PubMed

Zhai, Xiao-Ting; Chen, Jia-Quan; Jiang, Cui-Hua; Song, Jie; Li, Dong-Yu; Zhang, Hao; Jia, Xiao-Bin; Tan, Wei; Wang, Shu-Xia; Yang, Yi; Zhu, Fen-Xia

2016-12-24

Corydalis bungeana Turcz. (C. bungeana) is one of traditionally used medicines in China and possesses various biological effects, such as anti-inflammatory, antibacterial activity and inhibition of the immune function of the host. we studied the anti-inflammatory effect and molecular mechanism involved of C. bungeana both in vitro and in vivo model system in which the inflammatory response was induced by LPS treatment. Anti-inflammatory activity of C. bungeana was investigated by LPS-induced RAW 264.7 macrophages and BALB/c mice. The production and expression of pro-inflammatory cytokines were evaluated by Griess reagent, ELISA kits and RT-qPCR, respectively. Phosphorylation status of IκBα and p65 was illustrated by western blot assay. C. bungeana reduced the secretion of NO, TNF-α, IL-6 and IL-1β through inhibiting the protein expression of iNOS, TNF-α, IL-6 and IL-1β in vitro and in vivo. Western blot analysis suggested that C. bungeana supressed NF-κB activation via regulating the phosphorylation of IκBα and p65. Immunohistochemical assay also demostrated the histological inflammatory change in liver tissue. The results indicate that C. bungeana supresses the activation of NF-κB signaling pathway through inhibiting phosphorylation of IκBα and p65, which results in good anti-inflammatory effect. In addition, C. bungeana attenuates inflammatory reaction by supressing the expression of various inflammatory cytokines both in vivo and in vitro. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Indole-3-carbinol inhibits LPS-induced inflammatory response by blocking TRIF-dependent signaling pathway in macrophages.

PubMed

Jiang, Jun; Kang, Tae Bong; Shim, Do Wan; Oh, Na Hyun; Kim, Tack Joong; Lee, Kwang Ho

2013-07-01

Indole-3-carbinol (I3C), a natural hydrolysis product of glucobrassicin, is a member of the Brassica family of vegetables and is known to have various anti-cancer activities. In the present study, we assessed in vitro and in vivo anti-inflammatory effects of I3C and its molecular mechanisms. I3C attenuated the production of pro-inflammatory mediators such as NO, IL-6, and IL-1β in LPS-induced Raw264.7 cells and THP-1 cells through attenuation of the TRIF-dependent signaling pathway. Furthermore, I3C suppressed the infiltration of immune cells into the lung and pro-inflammatory cytokine production such as IL-6, TNF-α in broncho-alveolar lavage fluid (BALF) in the LPS-induced acute lung injury mouse model. I3C also suppressed IL-1β secretion in nigericin treated in vivo model. I3C has potent anti-inflammatory effects through regulating TRIF-dependent signaling pathways, suggesting that I3C may provide a valuable therapeutic strategy in treating various inflammatory diseases. Copyright © 2013 Elsevier Ltd. All rights reserved.

Specific inhibition of c-Jun N-terminal kinase delays preterm labour and reduces mortality

PubMed Central

Pirianov, Grisha; MacIntyre, David A; Lee, Yun; Waddington, Simon N; Terzidou, Vasso; Mehmet, Huseyin; Bennett, Phillip R

2015-01-01

Preterm labour (PTL) is commonly associated with infection and/or inflammation. Lipopolysaccharide (LPS) from different bacteria can be used to independently or mutually activate Jun N-terminal kinase (JNK)/AP1- or NF-κB-driven inflammatory pathways that lead to PTL. Previous studies using Salmonella abortus LPS, which activates both JNK/AP-1 and NF-κB, showed that selective inhibition of NF-κB delays labour and improves pup outcome. Where labour is induced using Escherichia coli LPS (O111), which upregulates JNK/AP-1 but not NF-κB, inhibition of JNK/AP-1 activation also delays labour. In this study, to determine the potential role of JNK as a therapeutic target in PTL, we investigated the specific contribution of JNK signalling to S. Abortus LPS-induced PTL in mice. Intrauterine administration of S. Abortus LPS to pregnant mice resulted in the activation of JNK in the maternal uterus and fetal brain, upregulation of pro-inflammatory proteins COX-2, CXCL1, and CCL2, phosphorylation of cPLA2 in myometrium, and induction of PTL. Specific inhibition of JNK by co-administration of specific D-JNK inhibitory peptide (D-JNKI) delayed LPS-induced preterm delivery and reduced fetal mortality. This is associated with inhibition of myometrial cPLA2 phosphorylation and proinflammatory proteins synthesis. In addition, we report that D-JNKI inhibits the activation of JNK/JNK3 and caspase-3, which are important mediators of neural cell death in the neonatal brain. Our data demonstrate that specific inhibition of TLR4-activated JNK signalling pathways has potential as a therapeutic approach in the management of infection/inflammation-associated PTL and prevention of the associated detrimental effects to the neonatal brain. PMID:26183892

The PPE18 protein of Mycobacterium tuberculosis inhibits NF-κB/rel-mediated proinflammatory cytokine production by upregulating and phosphorylating suppressor of cytokine signaling 3 protein.

PubMed

Nair, Shiny; Pandey, Akhilesh Datt; Mukhopadhyay, Sangita

2011-05-01

Mycobacterium tuberculosis bacteria are known to suppress proinflammatory cytokines like IL-12 and TNF-α for a biased Th2 response that favors a successful infection and its subsequent intracellular survival. However, the signaling pathways targeted by the bacilli to inhibit production of these cytokines are not fully understood. In this study, we demonstrate that the PPE18 protein of M. tuberculosis inhibits LPS-induced IL-12 and TNF-α production by blocking nuclear translocation of p50, p65 NF-κB, and c-rel transcription factors. We found that PPE18 upregulates the expression as well as tyrosine phosphorylation of suppressor of cytokine signaling 3 (SOCS3), and the phosphorylated SOCS3 physically interacts with IκBα-NF-κB/rel complex, inhibiting phosphorylation of IκBα at the serine 32/36 residues by IκB kinase-β, and thereby prevents nuclear translocation of the NF-κB/rel subunits in LPS-activated macrophages. Specific knockdown of SOCS3 by small interfering RNA enhanced IκBα phosphorylation, leading to increased nuclear levels of NF-κB/rel transcription factors vis-a-vis IL-12 p40 and TNF-α production in macrophages cotreated with PPE18 and LPS. The PPE18 protein did not affect the IκB kinase-β activity. Our study describes a novel mechanism by which phosphorylated SOCS3 inhibits NF-κB activation by masking the phosphorylation site of IκBα. Also, this study highlights the possible mechanisms by which the M. tuberculosis suppresses production of proinflammatory cytokines using PPE18.

Single-wall carbon nanohorns inhibited activation of microglia induced by lipopolysaccharide through blocking of Sirt3

NASA Astrophysics Data System (ADS)

Li, Lihong; Zhang, Jinqian; Yang, Yang; Wang, Qiang; Gao, Li; Yang, Yanlong; Chang, Tao; Zhang, Xingye; Xiang, Guoan; Cao, Yongmei; Shi, Zujin; Zhao, Ming; Gao, Guodong

2013-02-01

Single-wall carbon nanohorns (SWNHs) have been demonstrated to accumulate in cytotoxic levels within organs of various animal models and cell types, which emerge as a wide range of promising biomedical imaging. Septic encephalopathy (SE) is an early sign of sepsis and associated with an increased rate of morbidity and mortality. Microglia activation plays an important role in neuroinflammation, which contributes to neuronal damage. Inhibition of microglia activation may have therapeutic benefits, which can alleviate the progression of neurodegeneration. Therefore, we investigated the functional changes of mice microglia cell lines pre-treated with or without lipopolysaccharide (LPS) induced by SWNHs. To address this question, the research about direct role of SWNHs on the growth, proliferation, and apoptosis of microglia cell lines in mice (N9 and BV2) pre-treated with or without LPS had been performed. Our results indicate that the particle diameter of SWNHs in water is between 342 to 712 nm. The images in scanning electron microscope showed that SWNHs on polystyrene surface are individual particles. LPS induced activation of mice microglia, promoted its growth and proliferation, and inhibited its apoptosis. SWNHs inhibited proliferation, delayed mitotic entry, and promoted apoptosis of mice microglia cells. The effects followed gradually increasing cultured time and concentrations of SWNHs, especially in cells pre-treated with LPS. SWNHs induced a significantly increase in G1 phase and inhibition of S phase of mice microglia cells in a dose-manner dependent of SWNHs, especially in cells pre-treated with LPS. The transmission electron microscope images showed that individual spherical SWNH particles smaller than 100 nm in diameters were localized inside lysosomes of mice microglia cells. SWNHs inhibited mitotic entry, growth and proliferation of mice microglia cells, and promoted its apoptosis, especially in cells pre-treated with LPS. SWNHs inhibited expression

Mangiferin ameliorates colitis by inhibiting IRAK1 phosphorylation in NF-κB and MAPK pathways.

PubMed

Jeong, Jin-Ju; Jang, Se-Eun; Hyam, Supriya R; Han, Myung Joo; Kim, Dong-Hyun

2014-10-05

Mangiferin, a main constituent of the root of Anemarrhena asphodeloides and the leaves of Mangifera indica, inhibits NF-κB activation in macrophages. Therefore, we investigated effect of mangiferin on 2,3,4-trinitrobenzene sulfonic acid (TNBS)-induced colitis in mice and its anti-inflammatory mechanism in lipolysaccharide (LPS)- or peptidoglycan-stimulated mouse peritoneal macrophages. Mangiferin inhibited phosphorylation of nuclear factor-kappaB (NF-κB), interleukin-1 receptor-associated kinase 1 (IRAK1), and mitogen-activated protein kinases (MAPK) in peptidoglycan- or LPS-stimulated peritoneal macrophages. Mangiferin in the presence of SN50 inhibited LPS-stimulated NF-κB activation more potently than mangiferin alone. Mangiferin inhibited interaction of fluorescent p-IRAK1 antibody to LPS-stimulated peritoneal macrophages, but increased binding of fluorescent IRAK1 antibody. Mangiferin did not influence interaction of fluorescent LPS to toll-like receptor-4 on the macrophages. Molecular peak of mangiferin bound to IRAK1 was detected in the macrophages by mass analysis. Mangiferin (10 μM) inhibited LPS-stimulated expression of TNF-α, IL-1β and IL-6 by 81.0%, 89.5% and 88.3%, respectively, whereas it increased IL-10 expression by 131.8% compared to LPS-nontreated group. Mangiferin furthermore inhibited colon shortening, macroscopic score, and colonic myeloperoxidase activity in TNBS-induced colitic mice. Mangiferin inhibited TNBS-induced IRAK1 phosphorylation and NF-κB activation. Mangiferin suppressed TNBS-induced up-regulation of cyclooxygenase-2 and inducible NO synthase. Furthermore, mangiferin (20mg/kg) significantly inhibited TNF-α by 78%, IL-1β by 82%, and IL-6 expressions by 88% (P<0.05), but induced IL-10 expression to 79% of the normal control group (P<0.05). Based on these findings, mangiferin may ameliorate inflammatory diseases such as colitis by regulating NF-κB and MAPK signaling pathways through the inhibition of IRAK1 phosphorylation

Niclosamide suppresses RANKL-induced osteoclastogenesis and prevents LPS-induced bone loss

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cheon, Yoon-Hee; Kim, Ju-Young; Baek, Jong Min

Niclosamide (5-chloro-salicyl-(2-chloro-4-nitro) anilide) is an oral anthelmintic drug used for treating intestinal infection of most tapeworms. Recently, niclosamide was shown to have considerable efficacy against some tumor cell lines, including colorectal, prostate, and breast cancers, and acute myelogenous leukemia. Specifically, the drug was identified as a potent inhibitor of signal transducer and activator of transcription 3 (STAT3), which is associated with osteoclast differentiation and function. In this study, we assessed the effect of niclosamide on osteoclastogenesis in vitro and in vivo. Our in vitro study showed that receptor activator of nuclear factor-kappaB ligand (RANKL)-induced osteoclast differentiation was inhibited by niclosamide, due to inhibitionmore » of serine–threonine protein kinase (Akt) phosphorylation, inhibitor of nuclear factor-kappaB (IκB), and STAT3 serine{sup 727}. Niclosamide decreased the expression of the major transcription factors c-Fos and NFATc1, and thereafter abrogated the mRNA expression of osteoclast-specific genes, including TRAP, OSCAR, αv/β3 integrin (integrin αv, integrin β3), and cathepsin K (CtsK). In an in vivo model, niclosamide prevented lipopolysaccharide-induced bone loss by diminishing osteoclast activity. Taken together, our results show that niclosamide is effective in suppressing osteoclastogenesis and may be considered as a new and safe therapeutic candidate for the clinical treatment of osteoclast-related diseases such as osteoporosis. - Highlights: • We first investigated the anti-osteoclastogenic effects of niclosamide in vitro and in vivo. • Niclosamide impairs the activation of the Akt-IκB-STAT3 ser{sup 727} signaling axis. • Niclosamide acts a negative regulator of actin ring formation during osteoclast differentiation. • Niclosamide suppresses LPS-induced bone loss in vivo. • Niclosamide deserves new evaluation as a potential treatment target in various bone diseases.« less

Sinensetin attenuates LPS-induced inflammation by regulating the protein level of IκB-α.

PubMed

Shin, Hye-Sun; Kang, Seong-Il; Yoon, Seon-A; Ko, Hee-Chul; Kim, Se-Jae

2012-01-01

Sinensetin is one of the polymethoxyflavones (PMFs) having five methoxy groups on the basic benzo-γ-pyrone skeleton with a carbonyl group at the C(4) position. We investigated in this study the anti-inflammatory activity of sinensetin in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. Sinensetin showed anti-inflammatory activity by regulating the protein level of inhibitor κB-α (IκB-α).

Inhibitory effects of the methylene chloride fraction of JP05 on the production of inflammatory mediators in LPS-activated BV2 microglia.

PubMed

Jung, Hyo Won; Oh, Tae Woo; Jung, Jin Ki; Lee, Je-Hyun; Shin, Gil Jo; Park, Yong-Ki

2012-02-01

Excessive production of inflammatory mediators such as nitric oxide (NO) and proinflammatory cytokines from activated microglia in the central nervous system contributes to uncontrolled inflammation in neurodegenerative disorders. In this study, we investigated the anti-inflammatory activities of the methylene chloride fraction of JP05 (JP05-MC) on the production of inflammatory mediators in lipopolysaccharide (LPS)-stimulated BV2 mouse microglial cells, and its mechanism of action. JP05-MC significantly inhibited LPS-induced production of NO and the proinflammatory cytokines, TNF-α and IL-6, in BV2 cells. JP05-MC also attenuated the mRNA expression and protein levels of inducible nitric oxide synthase in LPS-induced BV2 cells. JP05-MC significantly attenuated LPS-elicited phosphorylation of the mitogen-activated protein kinase (MAPK), extracellular-signal-regulated kinase 1/2, and nuclear factor-κB (NF-κB) nuclear translocation in BV2 cells. Our results indicate that JP05-MC exerts anti-inflammatory properties via downregulation of inflammatory mediator gene transcription by suppressing the MAPK and NF-κB pathways, suggesting that JP05-MC may have therapeutic potential as an anti-inflammatory agent in neurodegenerative diseases.

Effects of voluntary wheel running on LPS-induced sickness behavior in aged mice.

PubMed

Martin, Stephen A; Pence, Brandt D; Greene, Ryan M; Johnson, Stephanie J; Dantzer, Robert; Kelley, Keith W; Woods, Jeffrey A

2013-03-01

Peripheral stimulation of the innate immune system with LPS causes exaggerated neuroinflammation and prolonged sickness behavior in aged mice. Regular moderate intensity exercise has been shown to exert anti-inflammatory effects that may protect against inappropriate neuroinflammation and sickness in aged mice. The purpose of this study was to test the hypothesis that voluntary wheel running would attenuate LPS-induced sickness behavior and proinflammatory cytokine gene expression in ~22-month-old C57BL/6J mice. Mice were housed with a running wheel (VWR), locked-wheel (Locked), or no wheel (Standard) for 10 weeks, after which they were intraperitoneally injected with LPS across a range of doses (0.02, 0.08, 0.16, 0.33 mg/kg). VWR mice ran on average 3.5 km/day and lost significantly more body weight and body fat, and increased their forced exercise tolerance compared to Locked and Shoebox mice. VWR had no effect on LPS-induced anorexia, adipsia, weight-loss, or reductions in locomotor activity at any LPS dose when compared to Locked and Shoebox groups. LPS induced sickness behavior in a dose-dependent fashion (0.33>0.02 mg/kg). Twenty-four hours post-injection (0.33 mg/kg LPS or Saline) we found a LPS-induced upregulation of whole brain TNFα, IL-1β, and IL-10 mRNA, and increased IL-1β and IL-6 in the spleen and liver; these effects were not attenuated by VWR. We conclude that VWR does not reduce LPS-induced exaggerated or prolonged sickness behavior in aged animals, or 24h post-injection (0.33 mg/kg LPS or Saline) brain and peripheral proinflammatory cytokine gene expression. The necessity of the sickness response is critical for survival and may outweigh the subtle benefits of exercise training in aged animals. Copyright © 2012 Elsevier Inc. All rights reserved.

Receptor Interacting Protein 3-Mediated Necroptosis Promotes Lipopolysaccharide-Induced Inflammation and Acute Respiratory Distress Syndrome in Mice.

PubMed

Wang, Linlin; Wang, Tingting; Li, Haobo; Liu, Qing; Zhang, Zhongjun; Xie, Wanli; Feng, Yinglu; Socorburam, Tumenjavkhlan; Wu, Gui; Xia, Zhengyuan; Wu, Qingping

2016-01-01

Necrosis amplifies inflammation and plays important roles in acute respiratory distress syndrome (ARDS). Necroptosis is a newly identified programmed necrosis that is mediated by receptor interacting protein 3 (RIP3). However, the potential involvement and impact of necroptosis in lipopolysaccharide (LPS)-induced ARDS remains unknown. We therefore explored the role and mechanism of RIP3-mediated necroptosis in LPS-induced ARDS. Mice were instilled with increasing doses of LPS intratracheally to induce different degrees of ARDS. Lung tissues were harvested for histological and TUNEL staining and western blot for RIP3, p-RIP3, X-linked inhibitor of apoptosis protein (XIAP), mixed lineage kinase domain-like protein (MLKL), total and cleaved caspases-3/8. Then, wild-type and RIP3 knock-out mice were induced ARDS with 30 mg/kg LPS. Pulmonary cellular necrosis was labeled by the propidium Iodide (PI) staining. Levels of TNF-a, Interleukin (IL)-1β, IL-6, IL-1α, IL-10 and HMGB1, tissue myeloperoxidase (MPO) activity, neutrophil counts and total protein concentration were measured. Results showed that in high dose LPS (30mg/kg and 40mg/kg) -induced severe ARDS, RIP3 protein was increased significantly, accompanied by increases of p-RIP3 and MLKL, while in low dose LPS (10mg/kg and 20mg/kg) -induced mild ARDS, apoptosis was remarkably increased. In LPS-induced severe ARDS, RIP3 knock-out alleviated the hypothermia symptom, increased survival rate and ameliorated the lung tissue injury RIP3 depletion also attenuated LPS-induced increase in IL-1α/β, IL-6 and HMGB1 release, decreased tissue MPO activity, and reduced neutrophil influx and total protein concentration in BALF in severe ARDS. Further, RIP3 depletion reduced the necrotic cells in the lung and decreased the expression of MLKL, but had no impact on cleaved caspase-3 in LPS-induced ARDS. It is concluded that RIP3-mediated necroptosis is a major mechanism of enhanced inflammation and lung tissue injury in high dose

Receptor Interacting Protein 3-Mediated Necroptosis Promotes Lipopolysaccharide-Induced Inflammation and Acute Respiratory Distress Syndrome in Mice

PubMed Central

Li, Haobo; Liu, Qing; Zhang, Zhongjun; Xie, Wanli; Feng, Yinglu; Socorburam, Tumenjavkhlan; Wu, Gui; Xia, Zhengyuan; Wu, Qingping

2016-01-01

Necrosis amplifies inflammation and plays important roles in acute respiratory distress syndrome (ARDS). Necroptosis is a newly identified programmed necrosis that is mediated by receptor interacting protein 3 (RIP3). However, the potential involvement and impact of necroptosis in lipopolysaccharide (LPS)-induced ARDS remains unknown. We therefore explored the role and mechanism of RIP3-mediated necroptosis in LPS-induced ARDS. Mice were instilled with increasing doses of LPS intratracheally to induce different degrees of ARDS. Lung tissues were harvested for histological and TUNEL staining and western blot for RIP3, p-RIP3, X-linked inhibitor of apoptosis protein (XIAP), mixed lineage kinase domain-like protein (MLKL), total and cleaved caspases-3/8. Then, wild-type and RIP3 knock-out mice were induced ARDS with 30 mg/kg LPS. Pulmonary cellular necrosis was labeled by the propidium Iodide (PI) staining. Levels of TNF-a, Interleukin (IL)-1β, IL-6, IL-1α, IL-10 and HMGB1, tissue myeloperoxidase (MPO) activity, neutrophil counts and total protein concentration were measured. Results showed that in high dose LPS (30mg/kg and 40mg/kg) -induced severe ARDS, RIP3 protein was increased significantly, accompanied by increases of p-RIP3 and MLKL, while in low dose LPS (10mg/kg and 20mg/kg) -induced mild ARDS, apoptosis was remarkably increased. In LPS-induced severe ARDS, RIP3 knock-out alleviated the hypothermia symptom, increased survival rate and ameliorated the lung tissue injury RIP3 depletion also attenuated LPS-induced increase in IL-1α/β, IL-6 and HMGB1 release, decreased tissue MPO activity, and reduced neutrophil influx and total protein concentration in BALF in severe ARDS. Further, RIP3 depletion reduced the necrotic cells in the lung and decreased the expression of MLKL, but had no impact on cleaved caspase-3 in LPS-induced ARDS. It is concluded that RIP3-mediated necroptosis is a major mechanism of enhanced inflammation and lung tissue injury in high dose

LPS-induced chemokine expression in both MyD88-dependent and -independent manners is regulated by Cot/Tpl2-ERK axis in macrophages.

PubMed

Bandow, Kenjiro; Kusuyama, Joji; Shamoto, Mitsuo; Kakimoto, Kyoko; Ohnishi, Tomokazu; Matsuguchi, Tetsuya

2012-05-21

LPS signaling is mediated through MyD88-dependent and -independent pathways, activating NF-?B, MAP kinases and IRF3. Cot/Tpl2 is an essential upstream kinase in LPS-mediated activation of ERKs. Here we explore the roles of MyD88 and Cot/Tpl2 in LPS-induced chemokine expression by studying myd88(-/-) and cot/tpl2(-/-) macrophages. Among the nine LPS-responsive chemokines examined, mRNA induction of ccl5, cxcl10, and cxcl13 is mediated through the MyD88-independent pathway. Notably, Cot/Tpl2-ERK signaling axis exerts negative effects on the expression of these three chemokines. In contrast, LPS-induced gene expression of ccl2, ccl7, cxcl2, cxcl3, ccl8, and cxcl9 is mediated in the MyD88-dependent manner. The Cot/Tpl2-ERK axis promotes the expression of the first four and inhibits the expression of the latter two. Thus, LPS induces expression of multiple chemokines through various signaling pathways in macrophages. Copyright © 2012 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

Oleamide suppresses lipopolysaccharide-induced expression of iNOS and COX-2 through inhibition of NF-kappaB activation in BV2 murine microglial cells.

PubMed

Oh, Young Taek; Lee, Jung Yeon; Lee, Jinhwa; Lee, Ju Hie; Kim, Ja-Eun; Ha, Joohun; Kang, Insug

2010-05-03

Oleamide (cis-9-octadecenamide) is an endogenous sleep-inducing fatty acid amide that accumulates in the cerebrospinal fluid of the sleep-deprived animals. Microglia are the major immune cells involved in neuroinflammation causing brain damage during infection, ischemia, and neurodegenerative disease. In this study, we examined the effects of oleamide on LPS-induced production of proinflammatory mediators and the mechanisms involved in BV2 microglia. Oleamide inhibited LPS-induced production of NO and prostaglandin E2 as well as expression of iNOS and COX-2. We showed that oleamide blocked LPS-induced NF-kappaB activation and phosphorylation of inhibitor kappaB kinase (IKK). We also showed that oleamide inhibited LPS-induced phosphorylation of Akt, p38 MAPK, and ERK, activation of PI 3-kinase, and accumulation of reactive oxygen species (ROS). Finally, we showed that a specific antagonist of the CB2 receptor, AM630, blocked the inhibitory effects of oleamide on LPS-induced production of proinflammatory mediators and activation of NF-kappaB. Taken together, our results suggest that oleamide shows an anti-inflammatory effect through inhibition of NF-kappaB activation in LPS-stimulated BV2 microglia. 2010 Elsevier Ireland Ltd. All rights reserved.

β-Glucan Reverses the Epigenetic State of LPS-Induced Immunological Tolerance

PubMed Central

Novakovic, Boris; Habibi, Ehsan; Wang, Shuang-Yin; Arts, Rob J.W.; Davar, Robab; Megchelenbrink, Wout; Kim, Bowon; Kuznetsova, Tatyana; Kox, Matthijs; Zwaag, Jelle; Matarese, Filomena; van Heeringen, Simon J.; Janssen-Megens, Eva M.; Sharifi, Nilofar; Wang, Cheng; Keramati, Farid; Schoonenberg, Vivien; Flicek, Paul; Clarke, Laura; Pickkers, Peter; Heath, Simon; Gut, Ivo; Netea, Mihai G.; Martens, Joost H.A.; Logie, Colin; Stunnenberg, Hendrik G.

2018-01-01

Summary Innate immune memory is the phenomenon whereby innate immune cells such as monocytes or macrophages undergo functional reprogramming after exposure to microbial components such as lipopolysaccharide (LPS). We apply an integrated epigenomic approach to characterize the molecular events involved in LPS-induced tolerance in a time-dependent manner. Mechanistically, LPS-treated monocytes fail to accumulate active histone marks at promoter and enhancers of genes in the lipid metabolism and phagocytic pathways. Transcriptional inactivity in response to a second LPS exposure in tolerized macrophages is accompanied by failure to deposit active histone marks at promoters of tolerized genes. In contrast, β-glucan partially reverses the LPS-induced tolerance in vitro. Importantly, ex vivo β-glucan treatment of monocytes from volunteers with experimental endotoxemia re-instates their capacity for cytokine production. Tolerance is reversed at the level of distal element histone modification and transcriptional reactivation of otherwise unresponsive genes. PMID:27863248

Friedelane-type triterpenoids as selective anti-inflammatory agents by regulation of differential signaling pathways in LPS-stimulated macrophages

DOE Office of Scientific and Technical Information (OSTI.GOV)

Villar-Lorenzo, Andrea, E-mail: avillar@iib.uam.es

A series of 31 pentacyclic triterpenoids isolated from the root barks of Celastrus vulcanicola and Maytenus jelskii were tested for cytotoxicity and inhibitory activity against lipopolysaccharide (LPS)-induced nitric oxide (NO) production in RAW 264.7 macrophages. Compounds 18 (C18) and 25 (C25) exhibited significant inhibition of LPS-induced NO release at 50 and 25 μM concentrations, respectively, and decreased mRNAs of pro-inflammatory cytokines. At the molecular level, C18 neither inhibited LPS-mediated phosphorylation of mitogen activated protein kinases (MAPKs) nor nuclear translocation of nuclear factor kappa beta (NFκB). Instead, C18 enhanced and prolonged nuclear translocation of nuclear factor-erythroid 2-related factor 2 (Nrf2) andmore » increased the expression of its target genes including hemeoxigenase 1 (HO1). C25 efficiently inhibited LPS-mediated phosphorylation of JNK, p38 and ERK, without affecting NFκB or Nrf2 signaling pathways. Both compounds reduced LPS-mediated processing of caspase-1 and the cleavage of interleukin 1β (IL1β) proform, reflecting their ability to target the inflammasome. C25 also counteracted LPS effects on iNOS expression and pro-inflammatory cytokines mRNA levels in Bv-2 microglial cells. The anti-inflammatory effect of both compounds was also assessed in human macrophages. Our results suggest that triterpenoids C18 and C25 possess anti-inflammatory effects, which may be therapeutically relevant for diseases linked to inflammation. - Highlights: • Compounds 18 (C18) and 25 (C25) exert anti-inflammatory effects in macrophages. • C18 enhanced nuclear translocation of Nrf2 and increased HO1 expression. • C25 inhibited the phosphorylation of JNK, p38 and ERK, members of the MAPKs family. • C25 reduced LPS-mediated processing of caspase-1 and the cleavage of interleukin 1β. • C18 and C25 may be therapeutic agents for diseases linked to inflammation.« less

Endogenous hydrogen sulfide regulates histone demethylase JMJD3-mediated inflammatory response in LPS-stimulated macrophages and in a mouse model of LPS-induced septic shock.

PubMed

Liu, Siyu; Wang, Xiling; Pan, Lilong; Wu, Weijun; Yang, Di; Qin, Ming; Jia, Wanwan; Xiao, Chenxi; Long, Fen; Ge, Junbo; Liu, Xinhua; Zhu, YiZhun

2018-03-01

Overproduction of inflammatory mediators contributes to uncontrolled inflammation during endotoxin shock. Cystathionine-γ-lyase (CSE), an enzyme involved in hydrogen sulfide (H 2 S) biosynthesis, has potential anti-inflammatory activity in a variety of inflammatory diseases. Jumonji domain-containing protein 3 (JMJD3), a histone 3 Lys27 (H3K27) demethylase, has been implicated in macrophage activation, but its function in CSE-mediated anti-inflammatory activities remains unknown. In the present study CSE was found to be upregulated in macrophages and mouse lipopolysaccharide (LPS) challenge models. LPS stimulation also enhanced the activation of JMJD3 and decreased H3K27me3 levels. JMJD3 knockdown upregulated H3K27me3 levels and attenuated the LPS-mediated inflammatory response. CSE knockout amplified the inflammatory cascade by increasing JMJD3 expression in septic mice. Similarly, enhanced production of inflammatory mediators by macrophages was mitigated by CSE overexpression via inhibition of JMJD3 expression. This is the first report indicating that inflammation enhanced CSE/H 2 S system biosynthesis, that in turn attenuated the LPS-triggered inflammatory response by regulating JMJD3 expression. Thus, the CSE/H 2 S system represents an epigenetic-based modification mechanism to prevent uncontrolled inflammation. Copyright © 2017 Elsevier Inc. All rights reserved.

Mangiferin alleviates lipopolysaccharide and D-galactosamine-induced acute liver injury by activating the Nrf2 pathway and inhibiting NLRP3 inflammasome activation.

PubMed

Pan, Chen-wei; Pan, Zhen-zhen; Hu, Jian-jian; Chen, Wei-lai; Zhou, Guang-yao; Lin, Wei; Jin, Ling-xiang; Xu, Chang-long

2016-01-05

Mangiferin, a glucosylxanthone from Mangifera indica, has been reported to have anti-inflammatory effects. However, the protective effects and mechanisms of mangiferin on liver injury remain unclear. This study aimed to determine the protective effects and mechanisms of mangiferin on lipopolysaccharide (LPS) and D-galactosamine (D-GalN)-induced acute liver injury. Mangiferin was given 1h after LPS and D-GalN treatment. The results showed that mangiferin inhibited the levels of serum ALT, AST, IL-1β, TNF-α, MCP-1, and RANTES, as well as hepatic malondialdehyde (MDA) and ROS levels. Moreover, mangiferin significantly inhibited IL-1β and TNF-α production in LPS-stimulated primary hepatocytes. Mangiferin was found to up-regulate the expression of Nrf2 and HO-1 in a dose-dependent manner. Furthermore, mangiferin inhibited LPS/d-GalN-induced hepatic NLRP3, ASC, caspase-1, IL-1β and TNF-α expression. In conclusion, mangiferin protected against LPS/GalN-induced liver injury by activating the Nrf2 pathway and inhibiting NLRP3 inflammasome activation. Copyright © 2015 Elsevier B.V. All rights reserved.

Ulinastatin post-treatment attenuates lipopolysaccharide-induced acute lung injury in rats and human alveolar epithelial cells

PubMed Central

Luo, Yunpeng; Che, Wen; Zhao, Mingyan

2017-01-01

Ulinastatin (UTI), a serine protease inhibitor, possesses anti-inflammatory properties and has been suggested to modulate lipopolysaccharide (LPS)-induced acute lung injury (ALI). High-mobility group box 1 (HMGB1), a nuclear DNA-binding protein, plays a key role in the development of ALI. The aim of this study was to investigate whether UTI attenuates ALI through the inhibition of HMGB1 expression and to elucidate the underlying molecular mechanisms. ALI was induced in male rats by the intratracheal instillation of LPS (5 mg/kg). UTI was administered intraperitoneally 30 min following exposure to LPS. A549 alveolar epithelial cells were incubated with LPS in the presence or absence of UTI. An enzyme-linked immunosorbent assay was used to detect the levels of inflammatory cytokines. Western blot analysis was performed to detect the changes in the expression levels of Toll-like receptor 2/4 (TLR2/4) and the activation of nuclear factor-κB (NF-κB). The results revealed that UTI significantly protected the animals from LPS-induced ALI, as evidenced by the decrease in the lung wet to dry weight ratio, total cells, neutrophils, macrophages and myeloperoxidase activity, associated with reduced lung histological damage. We also found that UTI post-treatment markedly inhibited the release of HMGB1 and other pro-inflammatory cytokines. Furthermore, UTI significantly inhibited the LPS-induced increase in TLR2/4 protein expression and NF-κB activation in lung tissues. In vitro, UTI markedly inhibited the expression of TLR2/4 and the activation of NF-κB in LPS-stimulated A549 alveolar epithelial cells. The findings of our study indicate that UTI attenuates LPS-induced ALI through the inhibition of HMGB1 expression in rats. These benefits are associated with the inhibition of the activation of the TLR2/4-NF-κB pathway by UTI. PMID:27959396

Sambulin A and B, non-glycosidic iridoids from Sambucus ebulus, exert significant in vitro anti-inflammatory activity in LPS-induced RAW 264.7 macrophages via inhibition of MAPKs's phosphorylation.

PubMed

Balkan, İrem Atay; İlter Akülke, Ayca Zeynep; Bağatur, Yeşim; Telci, Dilek; Gören, Ahmet Ceyhan; Kırmızıbekmez, Hasan; Yesilada, Erdem

2017-07-12

The leaves of Sambucus ebulus L. (Adoxaceae) are widely used in Turkish folk medicine particularly against inflammatory disorders. The fresh leaves after wilted over fire or the poultices prepared are directly applied externally to heal burns, edema, eczema, urticarial and abscess. Two iridoids were recently isolated (sambulin A, sambulin B) from the leaves of S. ebulus. This study aims to investigate the in vitro anti-inflammatory activities of these iridoids on LPS-induced RAW 264.7 macrophages. Raw 264.7 macrophages were treated with 12.5, 25 and 50µg/ml Sambulin A and 6.25, 12.5 and 25µg/ml Sambulin B and induced with 1µg/ml lipopolysaccaharides (LPS). Effect of the compounds on nitric oxide (NO) production and cytokines (TNFα, IL-6) were determined by Griess and ELISA assays respectively. iNOS and the phosphorylation levels of MAPKs (ERK, JNK) were examined by Western Blot. Sambulin A and sambulin B inhibited 52.82% and 72.88% of NO production at 50 and 25µg/ml concentrations respectively. The levels of iNOS were significantly decreased by both molecules, sambulin B at 25µg/ml almost completely decreased iNOS levels (97.53%). Both molecules significantly inhibited TNFα productions. However, only sambulin B inhibited IL-6 production. Consequently, it was shown that sambulin B exerted its effect through the inhibition of ERK and JNK phosphorylations. The prominent bioactivities exerted by two iridoids will contribute to explanation of the usage of S. ebulus in traditional medicine against rheumatoid diseases. Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.

The inhibition of inducible nitric oxide synthase and oxidative stress by agmatine attenuates vascular dysfunction in rat acute endotoxemic model.

PubMed

El-Awady, Mohammed S; Nader, Manar A; Sharawy, Maha H

2017-10-01

Vascular dysfunction leading to hypotension is a major complication in patients with septic shock. Inducible nitric oxide synthase (iNOS) together with oxidative stress play an important role in development of vascular dysfunction in sepsis. Searching for an endogenous, safe and yet effective remedy was the chief goal for this study. The current study investigated the effect of agmatine (AGM), an endogenous metabolite of l-arginine, on sepsis-induced vascular dysfunction induced by lipopolysaccharides (LPS) in rats. AGM pretreatment (10mg/kg, i.v.) 1h before LPS (5mg/kg, i.v.) prevented the LPS-induced mortality and elevations in serum creatine kinase-MB isoenzyme (CK-MB) activity, lactate dehydrogenase (LDH) activity, C-reactive protein (CRP) level and total nitrite/nitrate (NOx) level after 24h from LPS injection. The elevation in aortic lipid peroxidation illustrated by increased malondialdehyde (MDA) content and the decrease in aortic glutathione (GSH) and superoxide dismutase (SOD) were also ameliorated by AGM. Additionally, AGM prevented LPS-induced elevation in mRNA expression of iNOS, while endothelial NOS (eNOS) mRNA was not affected. Furthermore AGM prevented the impaired aortic contraction to KCl and phenylephrine (PE) and endothelium-dependent relaxation to acetylcholine (ACh) without affecting endothelium-independent relaxation to sodium nitroprusside (SNP). AGM may represent a potential endogenous therapeutic candidate for sepsis-induced vascular dysfunction through its inhibiting effect on iNOS expression and oxidative stress. Copyright © 2017 Elsevier B.V. All rights reserved.

Overexpression of Hsp20 Prevents Endotoxin-Induced Myocardial Dysfunction and Apoptosis via Inhibition of NF-κB Activation

PubMed Central

Wang, Xiaohong; Zingarelli, Basilia; Connor, Michael O’; Zhang, Pengyuan; Adeyemo, Adeola; Kranias, Evangelia G.; Wang, Yigang; Fan, Guo-Chang

2009-01-01

The occurrence of cardiovascular dysfunction in sepsis is associated with a significantly increased mortality rate of 70% to 90% compared with 20% in septic patients without cardiovascular impairment. Thus, rectification or blockade of myocardial depressant factors should partly ameliorate sepsis progression. Heat shock protein 20 (Hsp20) has been shown to enhance myocardial contractile function and protect against doxorubicin-induced cardiotoxicity. To investigate the possible role of Hsp20 in sepsis-mediated cardiac injury, we first examined the expression profiles of five major Hsps in response to lipopolysaccharide (LPS) challenge, and observed that only the expression of Hsp20 was downregulated in LPS-treated myocardium, suggesting that this decrease might be one of mechanisms contributing to LPS-induced cardiovascular defects. Further studies using loss-of-function and gain-of function approaches in adult rat cardiomyocytes verified that reduced Hsp20 levels were indeed correlated with the impaired contractile function. In fact, overexpression of Hsp20 significantly enhanced cardiomyocyte contractility upon LPS treatment. Moreover, after administration of LPS (25μg/g) in vivo, Hsp20 transgenic mice (10-fold overexpression) displayed: 1) an improvement in myocardial function; 2) reduced the degree of cardiac apoptosis; and 3) decreased NF-κB activity, accompanied with reduced myocardial cytokines IL-1β and TNF-α production, compared to the LPS-treated non-transgenic littermate controls. Thus, the increases in Hsp20 levels can protect against LPS-induced cardiac apoptosis and dysfunction, associated with inhibition of NF-κB activity, suggesting that Hsp20 may be a new therapeutic agent for the treatment of sepsis. PMID:19501592

Leonurine exerts anti-inflammatory effect by regulating inflammatory signaling pathways and cytokines in LPS-induced mouse mastitis.

PubMed

Song, Xiaojing; Wang, Tiancheng; Zhang, Zecai; Jiang, Haichao; Wang, Wei; Cao, Yongguo; Zhang, Naisheng

2015-02-01

Bovine mastitis is defined as the inflammation of mammary gland and is the most multiple diseases in dairy cattle. There is still no effective treatment now. Leonurine, extracted from Leonurus cardiaca, has been proved to have anti-inflammatory effect. In the present study, we utilized a mouse mastitis model to study the effect of leonurine on LPS-induced mastitis. Leonurine was administered three times during the 24 h after inducing infection in the mammary gland. The results showed that leonurine significantly alleviated LPS-induced histopathological changes, downregulated the levels of pro-inflammatory cytokines tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), upregulated the level of anti-inflammatory cytokine interleukin-10 (IL-10), and inhibited the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2). Further study revealed that leonurine inhibited the expression of Toll-like receptor 4 (TLR4) and the activation of nuclear factor-kappaB (NF-κB) and the phosphorylation of p38, extracellular signal-regulated kinase (ERK), and Jun N-terminal kinase (JNK). Therefore, the results demonstrated that leonurine could downregulate the expression of TNF-α, IL-6, iNOS, and COX-2 and upregulate the expression of IL-10 mainly by inhibiting the expression of TLR4 and the activation of NF-κB and the phosphorylation of p38, ERK, and JNK. Leonurine may be a potential agent for mastitis therapy.

Cannabidiol improves lung function and inflammation in mice submitted to LPS-induced acute lung injury.

PubMed

Ribeiro, A; Almeida, V I; Costola-de-Souza, C; Ferraz-de-Paula, V; Pinheiro, M L; Vitoretti, L B; Gimenes-Junior, J A; Akamine, A T; Crippa, J A; Tavares-de-Lima, W; Palermo-Neto, J

2015-02-01

We have previously shown that the prophylactic treatment with cannabidiol (CBD) reduces inflammation in a model of acute lung injury (ALI). In this work we analyzed the effects of the therapeutic treatment with CBD in mice subjected to the model of lipopolysaccharide (LPS)-induced ALI on pulmonary mechanics and inflammation. CBD (20 and 80 mg/kg) was administered (i.p.) to mice 6 h after LPS-induced lung inflammation. One day (24 h) after the induction of inflammation the assessment of pulmonary mechanics and inflammation were analyzed. The results show that CBD decreased total lung resistance and elastance, leukocyte migration into the lungs, myeloperoxidase activity in the lung tissue, protein concentration and production of pro-inflammatory cytokines (TNF and IL-6) and chemokines (MCP-1 and MIP-2) in the bronchoalveolar lavage supernatant. Thus, we conclude that CBD administered therapeutically, i.e. during an ongoing inflammatory process, has a potent anti-inflammatory effect and also improves the lung function in mice submitted to LPS-induced ALI. Therefore the present and previous data suggest that in the future cannabidiol might become a useful therapeutic tool for the attenuation and treatment of inflammatory lung diseases.

Gamma-tocotrienol inhibits lipopolysaccharide-induced interlukin-6 and granulocyte-colony stimulating factor by suppressing C/EBP-β and NF-κB in macrophages

PubMed Central

Wang, Yun; Jiang, Qing

2012-01-01

Cytokines generated from macrophages contributes to pathogenesis of inflammation-associated diseases. Here we show that gamma-tocotrienol (γ-TE), a natural vitamin E form, inhibits lipopolysaccharide (LPS)-induced interleukin-6 (IL-6) production without affecting TNFα, IL-10 or cyclooxygenase-2 (COX-2) up-regulation in murine RAW267.4 macrophages. Mechanistic studies indicate that nuclear factor (NF)-κB, but not JNK, p38 or ERK MAP kinases, is important to IL-6 production and γ-TE treatment blocks NF-κB activation. In contrast, COX-2 appears to be regulated by p38 MAPK in RAW cells, but γ-TE has no effect on LPS-stimulated p38 phosphorylation. Despite necessary for IL-6, NF-κB activation by TNFα or other cytokines is not sufficient for IL-6 induction with exception of LPS. CCAAT-enhancer binding protein β (C/EBPβ) appears to be involved in IL-6 formation, because LPS induces C/EBPβ up-regulation, which parallels IL-6 production, and knockdown of C/EBPβ with siRNA results in diminished IL-6. LPS but not individual cytokines is capable of stimulating C/EBPβ and IL-6 in macrophages. Consistent with its dampening effect on IL-6, γ-TE blunts LPS-induced up-regulation of C/EBPβ without affecting C/EBPδ. γ-TE also decreases LPS-stimulated granulocyte-colony stimulating factor (G-CSF), a C/EBPβ target gene. Compared with RAW267.4 cells, γ-TE shows similar or stronger inhibitory effects on LPS-triggered activation of NF-κB, C/EPBβ and C/EBPδ, and more potently suppresses IL-6 and G-CSF in bone marrow-derived macrophages. Our study demonstrates that γ-TE has anti-inflammatory activities by inhibition of NF-κB and C/EBPs activation in macrophages. PMID:23246159

Anti-inflammatory effects of shea butter through inhibition of iNOS, COX-2, and cytokines via the Nf-κB pathway in LPS-activated J774 macrophage cells.

PubMed

Verma, Nandini; Chakrabarti, Rina; Das, Rakha H; Gautam, Hemant K

2012-01-12

Shea butter is traditionally used in Africa for its anti-inflammatory and analgesic effects. In this study we explored the anti-inflammatory activities of the methanolic extract of shea butter (SBE) using lipopolysaccharide (LPS)-induced murine macrophage cell line J774. It was observed that SBE significantly reduced the levels of LPS-induced nitric oxide, Tumor necrosis factor-α (TNF-α), interleukins, 1β (IL-1β), and -12 (IL-12) in the culture supernatants in a dose dependent manner. Expression of pro-inflammatory enzymes, inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2) were also inhibited by SBE. These anti-inflammatory effects were due to an inhibitory action of SBE on LPS-induced iNOS, COX-2, TNF-α, IL-1β, and IL-12 mRNA expressions. Moreover, SBE efficiently suppressed IκB phosphorylation and NF-κB nuclear translocation induced by LPS. These findings explain the molecular bases of shea butter's bioactivity against various inflammatory conditions and substantiate it as a latent source of novel therapeutic agents.

Vaspin protects against LPS-induced ARDS by inhibiting inflammation, apoptosis and reactive oxygen species generation in pulmonary endothelial cells via the Akt/GSK-3β pathway

PubMed Central

Qi, Di; Wang, Daoxin; Zhang, Chunrong; Tang, Xumao; He, Jing; Zhao, Yan; Deng, Wang; Deng, Xinyu

2017-01-01

Acute respiratory distress syndrome (ARDS) is characterized by uncontrolled extravasation of protein-rich fluids, which is caused by disruption and dysfunction of the barrier of pulmonary endothelial cells (ECs). Visceral adipose tissue-derived serine protease inhibitor (vaspin) is a novel adipokine with pleiotropic properties, which has been reported to exert beneficial effects against obesity-associated systemic vascular diseases; however, its effects on ARDS remain unknown. In the present study, mice were subjected to systemic administration of adenoviral vector expressing vaspin (Ad-vaspin) to examine its effects on lipopolysaccharide (LPS)-induced ARDS in vivo. Histological analysis was then conducted, and cytokine [tumor necrosis factor (TNF)-α, interleukin (IL)-6 and IL-10] levels, and intercellular cell adhesion molecule-1 (ICAM-1) and adherens junctions (AJs) expression were detected. In addition, human pulmonary microvascular ECs (HPMECs) were treated with recombinant human (rh)-vaspin to further investigate its molecular basis and underlying mechanism. The mRNA expression levels of inflammatory cytokines (TNF-α and IL-6) and endothelial-specific adhesion markers [vascular cell adhesion molecule-1 and E-selectin], activation of nuclear factor-κB, and cell viability and apoptosis were then examined. Furthermore, the expression of AJs and organization of the cytoskeleton, as well as expression and activity of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase and generation of reactive oxygen species (ROS) were determined. The results indicated that Ad-vaspin protected against LPS-induced ARDS by alleviating the pulmonary inflammatory response and pulmonary EC barrier dysfunction in mice, which was accompanied by activation of the protein kinase B (Akt)/glycogen synthase kinase (GSK)-3β pathway. In addition, pretreatment of HPMECs with rh-vaspin attenuated inflammation, apoptosis and ROS generation without alterations in AJs and cytoskeletal

Daphnetin reduces endotoxin lethality in mice and decreases LPS-induced inflammation in Raw264.7 cells via suppressing JAK/STATs activation and ROS production.

PubMed

Shen, Lei; Zhou, Ting; Wang, Jing; Sang, Xiumei; Lan, Lei; Luo, Lan; Yin, Zhimin

2017-07-01

Here, we used various approaches to investigate the suppressive role of daphnetin in LPS-induced inflammatory response, with the goal to understand the underlining molecular mechanism by which daphnetin regulated these processes. We examined the survival rate and the lung injury in the mice model of LPS-induced endotoxemia. The production of pro-inflammatory factors including tumor necrosis factor α (TNF-α), interleukin-1β (IL-1β), IL-6, nitric oxide (NO), and prostaglandin E2 (PGE2) was measured by ELISA and nitrite analysis, respectively. The expression of inducible NO synthase (iNOS), cyclooxygenase 2 (COX-2), and the activation of signaling molecules was determined by immunoblotting. The production of reactive oxygen species (ROS) was measured by the ROS assay. In vivo study showed that daphnetin enhanced the survival rate and reduced the lung injury in mice with LPS-induced endotoxemia. Both in vivo and in vitro study showed that daphnetin prevented the production of pro-inflammatory factors including TNF-α, IL-1β, IL-6, NO, and PGE2 after LPS challenge. In Raw264.7 cells, we found that daphnetin reduced LPS-induced expression of iNOS and COX-2, and suppressed LPS-induced ROS production. In addition, we found that daphnetin suppressed the activation of JAK/STATs pathway and inhibited the nucleus import of STAT1 and STAT3. Here, our results indicate that daphnetin shows anti-inflammatory properties, at least in part, through suppressing LPS-induced activation of JAK/STATs cascades and ROS production.

Isoflavone-free soy protein diet inhibits LPS-induced inflammatory responses

USDA-ARS?s Scientific Manuscript database

Recently, we showed reduced atherosclerotic lesions in a hyperlipidemic mouse model fed isoflavone-free soy protein diet (SPI–) compared to casein (CAS)-fed mice, despite unchanged serum lipid levels. However, the molecular mechanisms contributing to the atheroprotective effect of soy-based diets is...

Adjudin attenuates lipopolysaccharide (LPS)- and ischemia-induced microglial activation

PubMed Central

Shao, Jiaxiang; Liu, Tengyuan; Xie, Qian Reuben; Zhang, Tingting; Yu, Hemei; Wang, Boshi; Ying, Weihai; Mruk, Dolores D.; Silvestrini, Bruno; Cheng, C. Yan; Xia, Weiliang

2014-01-01

Neuroinflammation caused by microglial activation plays a key role in ischemia, neurodegeneration and many other CNS diseases. In this study, we found that Adjudin, a potential non-hormonal male contraceptive, exhibits additional function to reduce the production of proinflammatory mediators. Adjudin significantly inhibited LPS-induced IL-6 release and IL-6, IL-1β, TNF-α expression in BV2 microglial cells. Furthermore, Adjudin exhibited anti-inflammatory properties by suppression of NF-κB p65 nuclear translocation and DNA binding activity as well as ERK MAPK phosphorylation. To determine the in vivo effect of Adjudin, we used a permanent middle cerebral artery occlusion (pMCAO) mouse model and found that Adjudin could reduce ischemia-induced CD11b expression, a marker of microglial activation. Furthermore, Adjudin treatment attenuated brain edema and neurological deficits after ischemia but did not reduce infarct volume. Thus, our data suggest that Adjudin may be useful for mitigating neuroinflammation. PMID:23084372

Anthocyanins Improve Hippocampus-Dependent Memory Function and Prevent Neurodegeneration via JNK/Akt/GSK3β Signaling in LPS-Treated Adult Mice.

PubMed

Khan, Muhammad Sohail; Ali, Tahir; Kim, Min Woo; Jo, Myeung Hoon; Chung, Jong Il; Kim, Myeong Ok

2018-05-19

Microglia plays a critical role in the brain and protects neuronal cells from toxins. However, over-activation of microglia leads to deleterious effects. Lipopolysaccharide (LPS) has been reported to affect neuronal cells via activation of microglia as well as directly to initiate neuroinflammation. In the present study, we evaluated the anti-inflammatory and anti-oxidative effect of anthocyanins against LPS-induced neurotoxicity in an animal model and in cell cultures. Intraperitoneal injections of LPS (250 μg/kg/day for 1 week) induce ROS production and promote neuroinflammation and neurodegeneration which ultimately leads to memory impairment. However, anthocyanins treatment at a dose of 24 mg/kg/day for 2 weeks (1 week before and 1 week co-treated with LPS) prevented ROS production, inhibited neuroinflammation and neurodegeneration, and improved memory functions in LPS-treated mice. Both histological and immunoblot analysis indicated that anthocyanins reversed the activation of JNK, prevented neuroinflammation by lowering the levels of inflammatory markers (p-NF-kB, TNF-α, and IL-1β), and reduced neuronal apoptosis by reducing the expression of Bax, cytochrome c, cleaved caspase-3, and cleaved PARP-1, while increasing the level of survival proteins p-Akt, p-GSK3β, and anti-apoptotic Bcl-2 protein. Anthocyanins treatment increased the levels of memory-related pre- and post-synaptic proteins and improved the hippocampus-dependent memory in the LPS-treated mice. Overall, this data suggested that consumption of naturally derived anti-oxidant agent such as anthocyanins ameliorated several pathological events in the LPS-treated animal model and we believe that anthocyanins would be a safe therapeutic agent for slowing the inflammation-induced neurodegeneration in the brain against several diseases such as Alzheimer's disease and Parkinson's disease.

Extract from Nandina domestica inhibits lipopolysaccharide-induced cyclooxygenase-2 expression in human pulmonary epithelial A549 cells.

PubMed

Ueki, Takuro; Akaishi, Tatsuhiro; Okumura, Hidenobu; Abe, Kazuho

2012-01-01

Extract from fruits of Nandina domestica THUNBERG (NDE) has been used to improve cough and breathing difficulty in Japan for many years. To explore whether NDE may alleviate respiratory inflammation, we investigated its effect on expression of cyclooxygenase-2 (COX-2) and production of prostaglandin E₂ (PGE₂) in human pulmonary epithelial A549 cells in culture. Treatment with lipopolysaccharide (LPS; 6 µg/mL) resulted in an increase of COX-2 expression and PGE₂ production in A549 cells. Both the LPS-induced COX-2 expression and PGE₂ production were significantly inhibited by NDE (1-10 µg/mL) in a concentration-dependent manner. NDE did not affect COX-1 expression nor COX activity. These results suggest that NDE downregulates LPS-induced COX-2 expression and inhibits PGE₂ production in pulmonary epithelial cells. Furthermore, higenamine and nantenine, two major constituents responsible for tracheal relaxing effect of NDE, did not mimic the inhibitory effect of NDE on LPS-induced COX-2 expression in A549 cells. To identify active constituent(s) of NDE responsible for the anti-inflammatory effect, NDE was introduced in a polyaromatic absorbent resin column and stepwise eluted to yield water fraction, 20% methanol fraction, 40% methanol fraction, 99.8% methanol fraction, and 99.5% acetone fraction. However, none of these five fractions alone inhibited LPS-induced COX-2 expression. On the other hand, exclusion of water fraction from NDE abolished the inhibitory effect of NDE on LPS-induced COX-2 expression. These results suggest that constituent(s) present in water fraction is required but not sufficient for the anti-inflammatory activity of NDE, which may result from interactions among multiple constituents.

Docosahexaenoic acid antagonizes the boosting effect of palmitic acid on LPS inflammatory signaling by inhibiting gene transcription and ceramide synthesis

PubMed Central

Jin, Junfei; Lu, Zhongyang; Li, Yanchun; Cowart, L. Ashley; Lopes-Virella, Maria F.

2018-01-01

It is well known that saturated fatty acids (SFAs) and unsaturated fatty acid, in particular omega-3 polyunsaturated fatty acids (n-3 PUFAs), have different effects on inflammatory signaling: SFAs are pro-inflammatory but n-3 PUFAs have strong anti-inflammatory properties. We have reported that palmitic acid (PA), a saturated fatty acid, robustly amplifies lipopolysaccharide (LPS) signaling to upregulate proinflammatory gene expression in macrophages. We also reported that the increased production of ceramide (CER) via sphingomyelin (SM) hydrolysis and CER de novo synthesis plays a key role in the synergistic effect of LPS and PA on proinflammatory gene expression. However, it remains unclear if n-3 PUFAs are capable of antagonizing the synergistic effect of LPS and PA on gene expression and CER production. In this study, we employed the above macrophage culture system and lipidomical analysis to assess the effect of n-3 PUFAs on proinflammatory gene expression and CER production stimulated by LPS and PA. Results showed that DHA strongly inhibited the synergistic effect of LPS and PA on proinflammatory gene expression by targeting nuclear factor kappa B (NFκB)-dependent gene transcription. Results also showed that DHA inhibited the cooperative effect of LPS and PA on CER production by targeting CER de novo synthesis, but not SM hydrolysis. Furthermore, results showed that myriocin, a specific inhibitor of serine palmitoyltransferase, strongly inhibited both LPS-PA-stimulated CER synthesis and proinflammatory gene expression, indicating that CER synthesis is associated with proinflammatory gene expression and that inhibition of CER synthesis contributes to DHA-inhibited proinflammatory gene expression. Taken together, this study demonstrates that DHA antagonizes the boosting effect of PA on LPS signaling on proinflammatory gene expression by targeting both NFκB-dependent transcription and CER de novo synthesis in macrophages. PMID:29474492

Docosahexaenoic acid antagonizes the boosting effect of palmitic acid on LPS inflammatory signaling by inhibiting gene transcription and ceramide synthesis.

PubMed

Jin, Junfei; Lu, Zhongyang; Li, Yanchun; Cowart, L Ashley; Lopes-Virella, Maria F; Huang, Yan

2018-01-01

It is well known that saturated fatty acids (SFAs) and unsaturated fatty acid, in particular omega-3 polyunsaturated fatty acids (n-3 PUFAs), have different effects on inflammatory signaling: SFAs are pro-inflammatory but n-3 PUFAs have strong anti-inflammatory properties. We have reported that palmitic acid (PA), a saturated fatty acid, robustly amplifies lipopolysaccharide (LPS) signaling to upregulate proinflammatory gene expression in macrophages. We also reported that the increased production of ceramide (CER) via sphingomyelin (SM) hydrolysis and CER de novo synthesis plays a key role in the synergistic effect of LPS and PA on proinflammatory gene expression. However, it remains unclear if n-3 PUFAs are capable of antagonizing the synergistic effect of LPS and PA on gene expression and CER production. In this study, we employed the above macrophage culture system and lipidomical analysis to assess the effect of n-3 PUFAs on proinflammatory gene expression and CER production stimulated by LPS and PA. Results showed that DHA strongly inhibited the synergistic effect of LPS and PA on proinflammatory gene expression by targeting nuclear factor kappa B (NFκB)-dependent gene transcription. Results also showed that DHA inhibited the cooperative effect of LPS and PA on CER production by targeting CER de novo synthesis, but not SM hydrolysis. Furthermore, results showed that myriocin, a specific inhibitor of serine palmitoyltransferase, strongly inhibited both LPS-PA-stimulated CER synthesis and proinflammatory gene expression, indicating that CER synthesis is associated with proinflammatory gene expression and that inhibition of CER synthesis contributes to DHA-inhibited proinflammatory gene expression. Taken together, this study demonstrates that DHA antagonizes the boosting effect of PA on LPS signaling on proinflammatory gene expression by targeting both NFκB-dependent transcription and CER de novo synthesis in macrophages.

NEMO-Binding Domain Peptide Attenuates Lipopolysaccharide-Induced Acute Lung Injury by Inhibiting the NF-κB Signaling Pathway

PubMed Central

Huang, Jianhua; Li, Li; Yuan, Weifeng; Zheng, Linxin

2016-01-01

The aim of the present study is to investigate the protective effects and relevant mechanisms exerted by NEMO-binding domain peptide (NBD) against lipopolysaccharide- (LPS-) induced acute lung injury (ALI) in mice. The ALI model was induced by intratracheally administered atomized LPS (5 mg/kg) to BABL/c mice. Half an hour before LPS administration, we treated the mice with increasing concentrations of intratracheally administered NBD or saline aerosol. Two hours after LPS administration, each group of mice was sacrificed. We observed that NBD pretreatment significantly attenuated LPS-induced lung histopathological injury in a dose-dependent manner. Western blotting established that NBD pretreatment obviously attenuated LPS-induced IκB-α and NF-κBp65 activation and NOX1, NOX2, and NOX4 overexpression. Furthermore, NBD pretreatment increased SOD and T-AOC activity and decreased MDA levels in lung tissue. In addition, NBD also inhibited TNF-α and IL-1β secretion in BALF after LPS challenge. In conclusion, NBD protects against LPS-induced ALI in mice. PMID:27956761

Resolvin E1 (Rv E1 ) attenuates LPS induced inflammation and subsequent atrophy in C2C12 myotubes.

PubMed

Baker, Luke A; Martin, Neil R W; Kimber, Marc C; Pritchard, Gareth J; Lindley, Martin R; Lewis, Mark P

2018-03-25

Resolution of inflammation is now known to be an active process which in part is instigated and controlled by specialized pro-resolving lipid mediators (SPM's) derived from dietary omega-3 fatty acids. Resolvin E1 (R v E 1 ) is one of these SPM's derived from the omega-3 fatty acid eicosapentaenoic acid. Using both molecular and phenotypic functional measures we report that in a model of Lipopolysaccharide (LPS) induced inflammation, R v E 1 attenuated mRNA levels of both interlukin-6 and monocyte chemoattractant protein-1 whilst having no effect on tumor necrosis factor-α or interlukin-1β in C2C12 skeletal muscle myotubes. Findings at the molecular level were transferred into similar changes in extracellular protein levels of the corresponding genes with the greatest attenuation being noted in IL-6 protein concentrations. R v E 1 instigated beneficial morphological changes through the prevention of LPS induced skeletal muscle atrophy, in tandem with attenuation of the LPS induced reduction in contractile force in tissue engineered skeletal muscle. These findings demonstrate, in our model of endotoxin induced inflammation in skeletal muscle, that R v E 1 has pro-resolving properties in this cell type. Our data provides rationale for further investigation into the mechanistic action of R v E 1 in skeletal muscle, with the vision of having potential benefits for the prevention/resolution of in-vivo skeletal muscle atrophy. © 2018 Wiley Periodicals, Inc.

Inhibition of lipid A-mediated type I interferon induction by bactericidal/permeability-increasing protein (BPI).

PubMed

Azuma, Masahiro; Matsuo, Aya; Fujimoto, Yukari; Fukase, Koichi; Hazeki, Kaoru; Hazeki, Osamu; Matsumoto, Misako; Seya, Tsukasa

2007-03-09

Lipopolysaccharide (LPS), a major constituent of the outer membrane of gram-negative bacteria, consists of polysaccharides and a lipid structure named lipid A. Lipid A is a typical microbial pattern molecule that serves as a ligand for Toll-like receptor 4 (TLR4). TLR4 signals the presence of lipid A to recruit adaptor molecules and induces cytokines and type I interferon (IFN) by activating transcription factor, NF-kappaB or IRF-3. Here we showed that chemically synthesized TLR4-agonistic lipid A analogues but not antagonistic lipid A activate IFN-beta promoter in TLR4-expressing HEK293 cells. The amplitude of IFN-beta promoter activation was in parallel with that of NF-kappaB. LPS-binding protein (LBP) was required for efficient IFN-beta induction in this system, and this LBP activity was antagonized by bactericidal/permeability-increasing protein (BPI). Thus, we first show that BPI blocks the TLR4 responses by exogenous administration of BPI to lipid A-sensitive cells. Although the functional mechanism whereby extra-cellular BPI modulates the intra-cellular signal pathways selected by the TLR adaptors, MyD88 and TICAM-1 (TRIF), remains unknown, we infer that the lipid A portion of LPS participates in LBP-amplified IFN-beta induction and that BPI binding to LPS leads to inhibition of the activation of NF-kappaB and IFN-beta by LPS or agonistic lipid A via TLR4 in an extrinsic mode. BPI may serve as a therapeutic potential against endotoxin shock by acting as a regulator for the MyD88- and TICAM-1 pathways in the LPS-TLR4 signaling.

MAPK signaling is required for LPS-induced VEGF in pulp stem cells.

PubMed

Botero, T M; Son, J S; Vodopyanov, D; Hasegawa, M; Shelburne, C E; Nör, J E

2010-03-01

Caries-induced pulpitis is typically accompanied by an increase in dental pulp microvascular density. However, the mechanisms by which dental pulp cells recognize lipopolysaccharides (LPSs) remain unclear. We hypothesized that Porphyromonas endodontalis and Escherichia coli LPSs induce vascular endothelial growth factor (VEGF) expression in dental pulp stem cells (DPSC) and human dental pulp fibroblasts (HDPF) through mitogen-activated protein kinase (MAPK) signaling. ELISA, semi-quantitative RT-PCR, immunofluorescence, and Western blots were used. Here, we observed that LPSs induced VEGF expression in DPSC and HDPF cells, and both cell types express Toll-like receptor 4 (TLR- 4). Notably, LPS-induced VEGF is associated with phosphorylation of protein kinase C (PKC zeta) and extracellular signal-regulator kinase (ERK1/2) and is dependent upon MAPK activation. Analysis of these data, collectively, unveils a signaling pathway responsible for synthesis of VEGF by pulp cells and suggests a novel therapeutic target for the management of vascular responses in teeth with pulpitis.

The regulation of cytochrome P450 2E1 during LPS-induced inflammation in the rat

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abdulla, Dalya; Goralski, Kerry B.; College of Pharmacy, Burbidge Building, Dalhousie University, Halifax, Nova Scotia, B3H 3J5

2006-10-01

It is well known that inflammatory and infectious conditions differentially regulate cytochrome P450 (P450)-mediated drug metabolism in the liver. We have previously outlined a potential pathway for the downregulation in hepatic cytochrome P450 following LPS-mediated inflammation in the CNS (Abdulla, D., Goralski, K.B., Garcia Del Busto Cano, E., Renton, K.W., 2005. The signal transduction pathways involved in hepatic cytochrome P450 regulation in the rat during an LPS-induced model of CNS inflammation. Drug Metab. Dispos). The purpose of this study was to outline the effects of LPS-induced peripheral and central nervous system inflammation on hepatic cytochrome P450 2E1 (CYP2E1) in vivo,more » an enzyme that plays an important role in various physiological and pathological states. We report an increase in hepatic mRNA expression of CYP2E1 that occurred as early as 2-3 h following either the intraperitoneal (i.p.) injection of 5 mg/kg LPS or i.c.v. administration of 25 {mu}g of LPS. This increase in CYP2E1 mRNA expression was sustained for 24 h. In sharp contrast to the increase in hepatic CYP2E1 mRNA, we observed a significant reduction in the catalytic activity of this enzyme 24 h following either the i.c.v. or i.p. administration of LPS. Cycloheximide or actinomycin-D did not change the LPS-mediated downregulation in hepatic CYP2E1 catalytic activity. Our results support the idea that LPS acts at two different levels to regulate hepatic CYP2E1: a transcriptional level to increase CYP2E1 mRNA expression and a post-transcriptional level to regulate CYP2E1 protein and activity.« less

A herbal formula consisting of Rosae Multiflorae Fructus and Lonicerae Japonicae Flos inhibits inflammatory mediators in LPS-stimulated RAW 264.7 macrophages.

PubMed

Cheng, Brian Chi-Yan; Ma, Xiao-Qing; Kwan, Hiu-Yee; Tse, Kai-Wing; Cao, Hui-Hui; Su, Tao; Shu, Xin; Wu, Zheng-zhi; Yu, Zhi-ling

2014-05-14

A herbal formula (RL) consisting of Rosae Multiflorae Fructus (Yingshi) and Lonicerae Japonicae Flos (Jinyinhua) has been traditionally used to treat inflammatory disorders. This study aims to investigate the anti-inflammatory mode and mechanism of action of the ethanol extract of RL so as to provide a pharmacological basis for the use of RL in treating inflammatory diseases. RL consisting of Yingshi and Jinyinhua (in 5:3 ratio) was extracted using absolute ethanol. We investigated its effects on nitric oxide (NO), interleukin-6 (IL-6), tumour necrosis factor (TNF)-α, inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), mitogen-activated protein kinases (MAPKs) and nuclear factor κB (NFκB) in mouse RAW 264.7 macrophages activated with lipopolysaccharide (LPS). RL could decrease the secretion of NO, IL-6 and TNF-α into the culture medium and the cellular protein levels of iNOS and COX-2, which were associated with the reduction of the phosphorylation/activation of JNK and p38, and the inhibition of the transcriptional activity of NF-κB. The present study demonstrated an inhibitory effect of RL on the inflammatory mediators regulated by the NF-κB and MAPK signalling pathways in LPS-stimulated RAW 264.7 macrophages, providing a pharmacological basis for RL in the control of inflammatory disorders. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Neutral endopeptidase promotes phorbol ester-induced apoptosis in prostate cancer cells by inhibiting neuropeptide-induced protein kinase C delta degradation.

PubMed

Sumitomo, M; Shen, R; Goldberg, J S; Dai, J; Navarro, D; Nanus, D M

2000-12-01

Phorbol esters induce apoptosis in androgen-sensitive LNCaP cells, which express neutral endopeptidase (NEP), but not in androgen-independent prostate cancer (PC) cells, which lack NEP expression. We investigated the role of NEP in PC cell susceptibility to 12-O-tetradecanoylphorbol-13-acetate (TPA). Western analysis showed that expression of NEP and protein kinase Cdelta (PKCdelta) correlated with PC cell sensitivity to TPA-induced growth arrest and apoptosis in LNCaP cells and in TSU-Prl cells expressing an inducible wild-type NEP protein. Inhibition of NEP enzyme activity using the specific NEP inhibitor CGS24592, or inhibition of PKCdelta using Rottlerin at concentrations that inhibit PKCdelta but not PKCalpha, significantly inhibited TPA-induced growth inhibition and cell death. Furthermore, pulse-chase experiments showed PKCdelta is stabilized in LNCaP cells and in TSU-Pr1 cells overexpressing wild-type NEP compared with PC cells lacking NEP expression. This results from NEP inactivation of its neuropeptide substrates (bombesin and endothelin-1), which in the absence of NEP stimulate cSrc kinase activity and induce rapid degradation of PKCdelta protein. These results indicate that expression of enzymatically active NEP by PC cells is necessary for TPA-induced apoptosis, and that NEP inhibits neuropeptide-induced, cSrc-mediated PKCdelta degradation.

fLPS: Fast discovery of compositional biases for the protein universe.

PubMed

Harrison, Paul M

2017-11-13

Proteins often contain regions that are compositionally biased (CB), i.e., they are made from a small subset of amino-acid residue types. These CB regions can be functionally important, e.g., the prion-forming and prion-like regions that are rich in asparagine and glutamine residues. Here I report a new program fLPS that can rapidly annotate CB regions. It discovers both single-residue and multiple-residue biases. It works through a process of probability minimization. First, contigs are constructed for each amino-acid type out of sequence windows with a low degree of bias; second, these contigs are searched exhaustively for low-probability subsequences (LPSs); third, such LPSs are iteratively assessed for merger into possible multiple-residue biases. At each of these stages, efficiency measures are taken to avoid or delay probability calculations unless/until they are necessary. On a current desktop workstation, the fLPS algorithm can annotate the biased regions of the yeast proteome (>5700 sequences) in <1 s, and of the whole current TrEMBL database (>65 million sequences) in as little as ~1 h, which is >2 times faster than the commonly used program SEG, using default parameters. fLPS discovers both shorter CB regions (of the sort that are often termed 'low-complexity sequence'), and milder biases that may only be detectable over long tracts of sequence. fLPS can readily handle very large protein data sets, such as might come from metagenomics projects. It is useful in searching for proteins with similar CB regions, and for making functional inferences about CB regions for a protein of interest. The fLPS package is available from: http://biology.mcgill.ca/faculty/harrison/flps.html , or https://github.com/pmharrison/flps , or is a supplement to this article.

PKB/SGK-dependent GSK3-phosphorylation in the regulation of LPS-induced Ca2+ increase in mouse dendritic cells.

PubMed

Russo, Antonella; Schmid, Evi; Nurbaeva, Meerim K; Yang, Wenting; Yan, Jing; Bhandaru, Madhuri; Faggio, Caterina; Shumilina, Ekaterina; Lang, Florian

2013-08-02

The function of dendritic cells (DCs) is modified by glycogen synthase kinase GSK3 and GSK3 inhibitors have been shown to protect against inflammatory disease. Regulators of GSK3 include the phosphoinositide 3 kinase (PI3K) pathway leading to activation of protein kinase B (PKB/Akt) and serum and glucocorticoid inducible kinase (SGK) isoforms, which in turn phosphorylate and thus inhibit GSK3. The present study explored, whether PKB/SGK-dependent inhibition of GSK3 contributes to the regulation of cytosolic Ca(2+) concentration following stimulation with bacterial lipopolysaccharides (LPS). To this end DCs from mutant mice, in which PKB/SGK-dependent GSK3α,β regulation was disrupted by replacement of the serine residues in the respective SGK/PKB-phosphorylation consensus sequence by alanine (gsk3(KI)), were compared to DCs from respective wild type mice (gsk3(WT)). According to Western blotting, GSK3 phosphorylation was indeed absent in gsk3(KI) DCs. According to flow cytometry, expression of antigen-presenting molecule major histocompatibility complex II (MHCII) and costimulatory molecule CD86, was similar in unstimulated and LPS (1μg/ml, 24h)-stimulated gsk3(WT) and gsk3(KI) DCs. Moreover, production of cytokines IL-6, IL-10, IL-12 and TNFα was not significantly different in gsk3(KI) and gsk3(WT) DCs. In gsk3(WT) DCs, stimulation with LPS (1μg/ml) within 10min led to transient phosphorylation of GSK3. According to Fura2 fluorescence, LPS (1μg/ml) increased cytosolic Ca(2+) concentration, an effect significantly more pronounced in gsk3(KI) DCs than in gsk3(WT) DCs. Conversely, GSK3 inhibitor SB216763 (3-[2,4-Dichlorophenyl]-4-[1-methyl-1H-indol-3-yl]-1H-pyrrole-2,5-dione, 10μM, 30min) significantly blunted the increase of cytosolic Ca(2+) concentration following LPS exposure. In conclusion, PKB/SGK-dependent GSK3α,β activity participates in the regulation of Ca(2+) signaling in dendritic cells. Copyright © 2013 Elsevier Inc. All rights reserved.

A Novel Herbal Medicine KIOM-MA Exerts an Anti-Inflammatory Effect in LPS-Stimulated RAW 264.7 Macrophage Cells.

PubMed

Oh, You-Chang; Cho, Won-Kyung; Jeong, Yun Hee; Im, Ga Young; Kim, Aeyung; Hwang, Youn-Hwan; Kim, Taesoo; Song, Kwang Hoon; Ma, Jin Yeul

2012-01-01

KIOM-MA was recently reported as a novel herbal medicine effective for atopic dermatitis and asthma. In this study, we have demonstrated the inhibitory effect of KIOM-MA on proinflammatory mediator produced in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. KIOM-MA significantly inhibited the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) as well as nitric oxide (NO) and prostaglandin E(2) (PGE(2)). Consistent with the inhibitory effect on PGE(2), KIOM-MA suppresses the LPS-induced migration of macrophages and gelatinase activity and the expression of matrix metalloprotease-9 (MMP-9) in a dose-dependent manner. Additionally, KIOM-MA showed a strong suppressive effect on the inflammatory cytokines production such as tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6). We also found that KIOM-MA inhibits the activation of nuclear factor-κB (NF-κB) and represses the activity of extracellular signal-regulated kinase (ERK), p38, and c-Jun NH(2)-terminal kinase (JNK) mitogen-activated protein kinases (MAPKs). Taken together, we elucidated the mechanism of anti-inflammatory effect of KIOM-MA using RAW 264.7 cells stimulated by LPS.

A Novel Herbal Medicine KIOM-MA Exerts an Anti-Inflammatory Effect in LPS-Stimulated RAW 264.7 Macrophage Cells

PubMed Central

Oh, You-Chang; Cho, Won-Kyung; Jeong, Yun Hee; Im, Ga Young; Kim, Aeyung; Hwang, Youn-Hwan; Kim, Taesoo; Song, Kwang Hoon; Ma, Jin Yeul

2012-01-01

KIOM-MA was recently reported as a novel herbal medicine effective for atopic dermatitis and asthma. In this study, we have demonstrated the inhibitory effect of KIOM-MA on proinflammatory mediator produced in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. KIOM-MA significantly inhibited the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) as well as nitric oxide (NO) and prostaglandin E2 (PGE2). Consistent with the inhibitory effect on PGE2, KIOM-MA suppresses the LPS-induced migration of macrophages and gelatinase activity and the expression of matrix metalloprotease-9 (MMP-9) in a dose-dependent manner. Additionally, KIOM-MA showed a strong suppressive effect on the inflammatory cytokines production such as tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6). We also found that KIOM-MA inhibits the activation of nuclear factor-κB (NF-κB) and represses the activity of extracellular signal-regulated kinase (ERK), p38, and c-Jun NH2-terminal kinase (JNK) mitogen-activated protein kinases (MAPKs). Taken together, we elucidated the mechanism of anti-inflammatory effect of KIOM-MA using RAW 264.7 cells stimulated by LPS. PMID:23243447

Protective effects of ginsenoside Rg1 against lipopolysaccharide/d-galactosamine-induced acute liver injury in mice through inhibiting toll-like receptor 4 signaling pathway.

PubMed

Ning, Chenqing; Gao, Xiaoguang; Wang, Changyuan; Huo, Xiaokui; Liu, Zhihao; Sun, Huijun; Yang, Xiaobo; Sun, Pengyuan; Ma, Xiaodong; Meng, Qiang; Liu, Kexin

2018-06-11

Acute liver injury (ALI) is a dramatic liver disease characterized by large areas of inflammation in the liver. This study aimed to investigate the protective effects of ginsenoside Rg1 (Rg1), a biologically active component in Panax ginseng, on lipopolysaccharide/d-galactosamine (LPS/D-GalN)-induced ALI in mice, and meanwhile explore the molecular mechanism in vivo and in vitro. Mice were pretreated with Rg1 for three days prior to LPS (40 μg/kg)/D-GalN (700 mg/kg) administration. The results showed that Rg1 improved the survival rate and reduced the liver to body weight ratios in mice. Rg1 also reduced the production of oxidative markers such as MDA and MPO induced by LPS/D-GalN. In addition, Rg1 significantly decreased the production of inflammatory cytokines including TNF-α, IL-6, IL-1β, Mip-2, Mcp-1, iNOS, and increased the activity of anti-inflammatory cytokine IL-10. Moreover, Rg1 inhibited the protein expression of TLR4 and its downstream genes including NF-κB and MAPKs, which are involved in inflammatory response. Rg1 dramatically reduced oxidative stress by regulating the expression of efflux transporters Mrp2 and various enzymes including GCLC, GCLM, HO-1 and NQO1. However, the changes in these genes and protein induced by Rg1 were abrogated by TLR4 antagonist TAK-242 in vitro. In conclusion, Rg1 had hepatoprotective effect on LPS/D-GalN-induced ALI in mice. The protection may be associated with the inhibition of TLR4. These findings suggest that Rg1 may be a promising agent for prevention against ALI. Copyright © 2018 Elsevier B.V. All rights reserved.

Neuroprotection of Scutellarin is mediated by inhibition of microglial inflammatory activation.

PubMed

Wang, S; Wang, H; Guo, H; Kang, L; Gao, X; Hu, L

2011-06-30

Inhibition of microglial over-reaction and the inflammatory processes may represent a therapeutic target to alleviate the progression of neurological diseases, such as neurodegenerative diseases and stroke. Scutellarin is the major active component of Erigeron breviscapus (Vant.) Hand-Mazz, a herbal medicine in treatment of cerebrovascular diseases for a long time in the Orient. In this study, we explored the mechanisms of neuroprotection by Scutellarin, particularly its anti-inflammatory effects in microglia. We observed that Scutellarin inhibited lipopolysaccharide (LPS)-induced production of proinflammatory mediators such as nitric oxide (NO), tumor necrosis factor α (TNFα), interleukin-1β (IL-1β) and reactive oxygen species (ROS), suppressed LPS-stimulated inducible nitric oxide synthase (iNOS), TNFα, and IL-1β mRNA expression in rat primary microglia or BV-2 mouse microglial cell line. Scutellarin inhibited LPS-induced nuclear translocation and DNA binding activity of nuclear factor κB (NF-κB). It repressed the LPS-induced c-Jun N-terminal kinase (JNK) and p38 phosphorylation without affecting the activity of extracellular signal regulated kinase (ERK) mitogen-activated protein kinase. Moreover, Scutellarin also inhibited interferon-γ (IFN-γ)-induced NO production, iNOS mRNA expression and transcription factor signal transducer and activator of transcription 1α (STAT1α) activation. Concomitantly, conditioned media from Scutellarin pretreated BV-2 cells significantly reduced neurotoxicity compared with conditioned media from LPS treated alone. Together, the present study reported the anti-inflammatory activity of Scutellarin in microglial cells along with their underlying molecular mechanisms, and suggested Scutellarin might have therapeutic potential for various microglia mediated neuroinflammation. Copyright © 2011 IBRO. Published by Elsevier Ltd. All rights reserved.

LPS causes pericyte loss and microvascular dysfunction via disruption of Sirt3/angiopoietins/Tie-2 and HIF-2α/Notch3 pathways.

PubMed

Zeng, Heng; He, Xiaochen; Tuo, Qin-Hui; Liao, Duan-Fang; Zhang, Guo-Qiang; Chen, Jian-Xiong

2016-02-12

Recent studies reveal a crucial role of pericyte loss in sepsis-associated microvascular dysfunction. Sirtuin 3 (SIRT3) mediates histone protein post-translational modification related to aging and ischemic disease. This study investigated the involvement of SIRT3 in LPS-induced pericyte loss and microvascular dysfunction. Mice were exposed to LPS, expression of Sirt3, HIF-2α, Notch3 and angiopoietins/Tie-2, pericyte/endothelial (EC) coverage and vascular permeability were assessed. Mice treated with LPS significantly reduced the expression of SIRT3, HIF-2α and Notch3 in the lung. Furthermore, exposure to LPS increased Ang-2 while inhibited Ang-1/Tie-2 expression with a reduced pericyte/EC coverage. Intriguingly, knockout of Sirt3 upregulated Ang-2, but downregulated Tie-2 and HIF-2α/Notch3 expression which resulted in a dramatic reduction of pericyte/EC coverage and exacerbation of LPS-induced vascular leakage. Conversely, overexpression of Sirt3 reduced Ang-2 expression and increased Ang-1/Tie-2 and HIF-2α/Notch3 expression in the LPS treated mice. Overexpression of Sirt3 further prevented LPS-induced pericyte loss and vascular leakage. This was accompanied by a significant reduction of the mortality rate. Specific knockout of prolyl hydroxylase-2 (PHD2) increased HIF-2α/Notch3 expression, improved pericyte/EC coverage and reduced the mortality rate in the LPS-treated mice. Our study demonstrates the importance of SIRT3 in preserving vascular integrity by targeting pericytes in the setting of LPS-induced sepsis.

The anti-inflammatory effects of baicalin through suppression of NLRP3 inflammasome pathway in LPS-challenged piglet mononuclear phagocytes.

PubMed

Ye, Chun; Li, Sali; Yao, Wenxu; Xu, Lei; Qiu, Yinsheng; Liu, Yu; Wu, Zhongyuan; Hou, Yongqing

2016-04-01

In this study, the anti-inflammatory effects and mechanisms of baicalin on LPS-induced NLRP3 inflammatory pathway were investigated in piglet mononuclear phagocytes (control, LPS stimulation, LPS stimulation + 12.5 µg/ml baicalin, LPS stimulation + 25 µg/ml baicalin, LPS stimulation + 50 µg/ml baicalin and LPS stimulation + 100 µg/ml baicalin). The levels of reactive oxygen species (ROS), the secretion levels of IL-1β, IL-18 and TNF-α, mRNA expression levels of IL-1β, IL-18, TNF-α and NLRP3, as well as the protein levels of cleaved caspase-1 p20 were significantly increased after LPS-challengein vitro However, LPS stimulation did not influence apoptosis-associated speck-like protein and caspase-1 mRNA levels, which are also components of the NLRP3 inflammasome. Baicalin at 50 µg/ml and 100 µg/ml could inhibit the production of ROS, TNF-α, IL-1β and IL-18, and down-regulate mRNA expression of IL-1β, IL-18, TNF-α and NLRP3, as well as expression of cleaved caspase-1 p20. These results showed that the anti-inflammatory effects of baicalin occurred via the regulation of the release of ROS and mRNA expression of NLRP3. The anti-inflammatory activity of baicalin could be related to the suppression of NLRP3 inflammasome pathway under LPS stimulation. © The Author(s) 2016.

[The role of N-acetylcysteine against the injury of pulmonary artery induced by LPS].

PubMed

Huang, Xin-li; Ling, Yi-ling; Zhu, Tie-nian

2002-11-01

To investigate the alleviating effect of N-acetylcysteine (NAC) on lung injury induced by lipopolysaccharides (LPS) and its mechanism. The effects of NAC on changes of the pulmonary arterial reactivity and the ultrastructure of pulmonary arterial endothelium induced by LPS were observed with the isolated artery ring technique and scanning electron microscope (SEM). Malondialdehyde (MDA), nitric oxide (NO) contents and superoxide dismutase (SOD) activity of pulmonary artery tissues were detected. The exposure of pulmonary artery to LPS (4 microg/ml, 7 h) led to reduction of endothelium-dependent relaxation response to acetylcholine (ACh), which was reversed by the concomitant exposure to NAC (0.5 mmol/L, 7 h), whereas NAC itself had no effect on the response. Significant structural injury were observed under SEM in LPS group and alleviated the changes in LPS + NAC group. The MDA, NO contents increased but SOD activity decreased in LPS group, which were reversed by the concomitant exposure to NAC. NAC protects pulmonary artery endothelium and enhances endothelium-dependent relaxation response of pulmonary artery by antioxidation effect, which may be one of the mechanisms of its reversing pulmonary artery hypertension and following lung injury induced by LPS.

Cyanidin-3-O-beta-glucoside inhibits LPS-induced expression of inflammatory mediators through decreasing IkBa Phosphorylation in THP-1 Cells

USDA-ARS?s Scientific Manuscript database

Objective and design: As a common phytochemical, cyanidin 3-O-beta-glucoside (C3G) has a role in inhibiting inflammatory mediators; however, its mechanism of action remains unclear. The purpose of this study was to explore the effect of C3G on lipopolysaccharide (LPS)-stimulated TNFa and IL-6 expres...

Immunomodulatory effects of thalidomide analogs on LPS-induced plasma and hepatic cytokines in the rat.

PubMed

Fernández-Martínez, Eduardo; Morales-Ríos, Martha S; Pérez-Alvarez, Víctor; Muriel, Pablo

2004-10-01

Thalidomide has shown to inhibit, selectively and mainly the cytokine tumor necrosis factor-alpha (TNF-alpha), thus, thalidomide has inhibitory consequences on other cytokines; this is ascribed as an immunomodulatory effect. Novel thalidomide analogs are reported with immunomodulatory activity. The aim of this work was to synthesize some of these analogs and to assess them as immunomodulatory agents in an acute model of LPS-induced septic challenge in rat. Animal groups received orally twice a day vehicle carboxymethylcellulose (0.9%), or thalidomide in suspension (100mg/kg), or analogs in an equimolar dose. Two hours after last dose, rats were injected with saline (NaCl, 0.9%, i.p.) or LPS (5mg/kg, i.p.). Groups were sacrificed 2h after injection and samples of blood and liver were obtained. TNF-alpha, interleukin-6, -1beta, and -10 (IL-6, IL-1beta, IL-10) were quantified by enzyme linked immunosorbent assay (ELISA) and studied in plasma and liver. After 2h of LPS-induction, different patterns of measured cytokines were observed with thalidomide analogs administration evidencing their immunomodulatory effects. Interestingly, some analogs decreased significantly plasma and hepatic levels of LPS-induced proinflammatory TNF-alpha and others increased plasma concentration of anti-inflammatory IL-10. Thalidomide analogs also showed slight effects on the remaining proinflammatory cytokines. Differences among immunomodulatory effects of analogs can be related to potency, mechanism of action, and half lives. Thalidomide analogs could be used as a pharmacological tool and in therapeutics in the future.

Anti-inflammatory and Anti-oxidative Effects of Dexpanthenol on Lipopolysaccharide Induced Acute Lung Injury in Mice.

PubMed

Li-Mei, Wan; Jie, Tan; Shan-He, Wan; Dong-Mei, Meng; Peng-Jiu, Yu

2016-10-01

The aim of this study is to investigate the effects of dexpanthenol in a model of acute lung injury (ALI) induced by lipopolysaccharides (LPS). Lung injury was induced by exposure to atomized LPS. Mice were randomly divided into four groups: control group; Dxp (500 mg/kg) group; LPS group; LPS + Dxp (500 mg/kg) group. The effects of dexpanthenol on LPS-induced neutrophil recruitment, cytokine levels, total protein concentration, myeloperoxidase (MPO), malondialdehyde (MDA), superoxide dismutase (SOD), and glutathione (GSH) contents were examined. Additionally, lung tissue was examined by histology to investigate the changes in pathology in the presence and absence of dexpanthenol. In LPS-challenged mice, dexpanthenol significantly improved lung edema. Dexpanthenol also markedly inhibited the LPS-induced neutrophiles influx, protein leakage, and release of TNF-α and IL-6 in bronchoalveolar lavage fluid (BALF). Furthermore, dexpanthenol attenuated MPO activity and MDA contents and increased SOD and GSH activity in the LPS-challenged lung tissue. These data suggest that dexpanthenol protects mice from LPS-induced acute lung injury by its anti-inflammatory and anti-oxidative activities.

Effect of a kinin B2 receptor antagonist on LPS- and cytokine-induced neutrophil migration in rats

PubMed Central

Santos, Danielle R; Calixto, João B; Souza, Glória E P

2003-01-01

This study examines the involvement of kinins in neutrophil migration into rat subcutaneous air pouches triggered by lipopolysaccharide (LPS), as well as the putative roles played by kinin B1 and B2 receptors, tumour necrosis factor alpha (TNF-α), interleukin-1 beta (IL-1β) and selectins in this response. LPS (5 ng to 10 μg cavity−1) injected into the 6-day-old pouch induced a dose- and time-dependent neutrophil migration which peaked between 4 and 6 h, and was maximal following the dose of 100 ng cavity−1 (saline: 0.46±0.1; LPS: 43±3.70 × 106 cells cavity−1 at 6 h). Bradykinin (BK) (600 nmol) injected into the pouch of saline-treated rats induced only modest neutrophil migration (0.73±0.16 × 106 cells cavity−1). A more robust response to BK (3.2±0.25 × 106 cells cavity−1) was seen in animals pretreated with captopril, but this was still smaller than the responses to IL-1β or TNF-α (15 pmol: 23±2.2 × 106 and 75 pmol: 29.5±2 × 106 cells cavity−1, respectively). Nevertheless, the B1 agonist des-Arg9-BK (600 nmol) failed to induce neutrophil migration. HOE-140 (1 and 2 mg kg−1), a B2 receptor antagonist, reduced LPS-induced neutrophil migration. HOE-140 also reduced the neutrophil migration induced by BK, but had no effect on the migration promoted by IL-1β or TNF-α. des-Arg9-[Leu8]-BK, B1 receptor antagonist was ineffective in changing neutrophil migration caused by any of these stimuli. Neutrophil migration induced by LPS or BK was reduced by interleukin-1 receptor antagonist (IL-1ra) (1 mg kg−1), sheep anti-rat TNF serum (anti-TNF serum) (0.3 ml cavity−1), and the nonspecific selectin inhibitor fucoidin (10 mg kg−1). TNF-α levels in the pouch fluid were increased by LPS or BK injection, peaking at 0.5–1 h and gradually declining thereafter up to 6 h. IL-1β levels increased steadily throughout the 6 h period. HOE-140 markedly inhibited the rise in IL-1β and TNF-α levels in pouch fluid triggered by both stimuli. These

LPS from Escherichia coli protects against indomethacin-induced gastropathy in rats--role of ATP-sensitive potassium channels.

PubMed

Gomes, Antoniella S; Lima, Lívia M F; Santos, Camila L; Cunha, Fernando Q; Ribeiro, Ronaldo A; Souza, Marcellus H L P

2006-10-10

The effect of lipopolysaccharide (LPS) in gastric protection has not been elucidated, but ATP-sensitive potassium (K(ATP)) channels are known to be involved in gastric defense. We evaluated the effect of LPS administration on indomethacin-induced gastropathy, and the role of K(ATP) channels in this event. Rats received intravenous (i.v.) LPS administration. After 1/2, 6, 24 or 48 h, indomethacin was injected. 3H later, gastric damage and myeloperoxidase activity were determined. Another group received LPS and 5 h later, glibenclamide, diazoxide or glibenclamide plus diazoxide. After 1 h, the rats received indomethacin and 3 h later, gastric damage and myeloperoxidase activity were evaluated. LPS reduced dose dependently gastric damage and myeloperoxidase activity induced by indomethacin. Glibenclamide reversed this LPS effect on indomethacin-induced gastropathy. Glibenclamide plus diazoxide administration did not change this LPS effect. Thus LPS has a protective effect against indomethacin-induced gastropathy, probably through activation of K(ATP) channels.

Inhibition of acetylcholinesterase activity by rivastigmine decreases lipopolysaccharide-induced IL-1β expression in the hypothalamus of ewes.

PubMed

Herman, A P; Krawczyńska, A; Bochenek, J; Haziak, K; Antushevitch, H; Herman, A; Tomaszewska-Zaremba, D

2013-04-01

The present study was designed to determine the effect of subcutaneous rivastigmine treatment on IL-1β expression and IL-1 type I receptor (IL-1R1) gene expression in the hypothalamic structures (preoptic area [POA], anterior hypothalamus [AHA], and medial basal hypothalamus [MBH]) of ewes after lipopolysaccharide (LPS) treatment. Endotoxin treatment increased (P ≤ 0.01) both IL-1β and IL-1R1 gene expression in the POA, AHA, and MBH compared with the control group, whereas concomitant rivastigmine and LPS injection abolished this stimulatory effect. It was also found that LPS elevated (P ≤ 0.01) IL-1β concentration in the hypothalamus (71.0 ± 2.3 pg/mg) compared with controls (16.1 ± 3.6 pg/mg). The simultaneous injection of LPS and rivastigmine did not increase IL-1β concentration in the hypothalamus (24.6 ± 13.0 pg/mg). This central change in IL-1β synthesis seems to be an effect of acetylcholinesterase (AChE) inhibition by rivastigmine, which decreases (P ≤ 0.01) the activity of this enzyme from 78.5 ± 15.0 μmol · min(-1) · g(-1) of total protein in the control and 68.8 ± 9.8 μmol · min(-1) · g(-1) of total protein in LPS-treated animals to 45.2 ± 5.6 μmol · min(-1) · g(-1) of total protein in the rivastigmine and LPS-treated group. Our study showed that rivastigmine could effectively reverse the stimulatory effect of immune stress induced by LPS injection on IL-1β synthesis through a decrease in AChE activity in the hypothalamic area of sheep. Our results also proved that the cholinergic anti-inflammatory pathway could directly modulate the central response to endotoxin. Copyright © 2013 Elsevier Inc. All rights reserved.

Formononetin inhibits lipopolysaccharide-induced release of high mobility group box 1 by upregulating SIRT1 in a PPARδ-dependent manner.

PubMed

Hwang, Jung Seok; Kang, Eun Sil; Han, Sung Gu; Lim, Dae-Seog; Paek, Kyung Shin; Lee, Chi-Ho; Seo, Han Geuk

2018-01-01

The release of high mobility group box 1 (HMGB1) induced by inflammatory signals acts as a cellular alarmin to trigger a chain of inflammatory responses. Although the inflammatory actions of HMGB1 are well studied, less is known about the therapeutic agents that can impede its release. This study investigated whether the isoflavonoid formononetin can modulate HMGB1 release in cellular inflammatory responses. RAW264.7 murine macrophages were exposed to lipopolysaccharide (LPS) in the presence or absence of formononetin. The levels of HMGB1 release, sirtuin 1 (SIRT1) expression, and HMGB1 acetylation were analyzed by immunoblotting and real-time polymerase chain reaction. The effects of resveratrol and sirtinol, an activator and inhibitor of SIRT1, respectively, on LPS-induced HMGB1 release were also evaluated. Formononetin modulated cellular inflammatory responses by suppressing the release of HMGB1 by macrophages exposed to LPS. In RAW264.7 cells, formononetin significantly attenuated LPS-induced release of HMGB1 into the extracellular environment, which was accompanied by a reduction in its translocation from the nucleus to the cytoplasm. In addition, formononetin significantly induced mRNA and protein expression of SIRT1 in a peroxisome proliferator-activated receptor δ (PPARδ)-dependent manner. These effects of formononetin were dramatically attenuated in cells treated with small interfering RNA (siRNA) against PPARδ or with GSK0660, a specific inhibitor of PPARδ, indicating that PPARδ is involved in formononetin-mediated SIRT1 expression. In line with these effects, formononetin-mediated inhibition of HMGB1 release in LPS-treated cells was reversed by treatment with SIRT1-targeting siRNA or sirtinol, a SIRT1 inhibitor. By contrast, resveratrol, a SIRT1 activator, further potentiated the inhibitory effect of formononetin on LPS-induced HMGB1 release, revealing a possible mechanism by which formononetin regulates HMGB1 release through SIRT1. Furthermore

Formononetin inhibits lipopolysaccharide-induced release of high mobility group box 1 by upregulating SIRT1 in a PPARδ-dependent manner

PubMed Central

Hwang, Jung Seok; Kang, Eun Sil; Han, Sung Gu; Lim, Dae-Seog; Paek, Kyung Shin; Lee, Chi-Ho

2018-01-01

Background The release of high mobility group box 1 (HMGB1) induced by inflammatory signals acts as a cellular alarmin to trigger a chain of inflammatory responses. Although the inflammatory actions of HMGB1 are well studied, less is known about the therapeutic agents that can impede its release. This study investigated whether the isoflavonoid formononetin can modulate HMGB1 release in cellular inflammatory responses. Methods RAW264.7 murine macrophages were exposed to lipopolysaccharide (LPS) in the presence or absence of formononetin. The levels of HMGB1 release, sirtuin 1 (SIRT1) expression, and HMGB1 acetylation were analyzed by immunoblotting and real-time polymerase chain reaction. The effects of resveratrol and sirtinol, an activator and inhibitor of SIRT1, respectively, on LPS-induced HMGB1 release were also evaluated. Results Formononetin modulated cellular inflammatory responses by suppressing the release of HMGB1 by macrophages exposed to LPS. In RAW264.7 cells, formononetin significantly attenuated LPS-induced release of HMGB1 into the extracellular environment, which was accompanied by a reduction in its translocation from the nucleus to the cytoplasm. In addition, formononetin significantly induced mRNA and protein expression of SIRT1 in a peroxisome proliferator-activated receptor δ (PPARδ)-dependent manner. These effects of formononetin were dramatically attenuated in cells treated with small interfering RNA (siRNA) against PPARδ or with GSK0660, a specific inhibitor of PPARδ, indicating that PPARδ is involved in formononetin-mediated SIRT1 expression. In line with these effects, formononetin-mediated inhibition of HMGB1 release in LPS-treated cells was reversed by treatment with SIRT1-targeting siRNA or sirtinol, a SIRT1 inhibitor. By contrast, resveratrol, a SIRT1 activator, further potentiated the inhibitory effect of formononetin on LPS-induced HMGB1 release, revealing a possible mechanism by which formononetin regulates HMGB1 release

Structural basis of recognition of pathogen-associated molecular patterns and inhibition of proinflammatory cytokines by camel peptidoglycan recognition protein.

PubMed

Sharma, Pradeep; Dube, Divya; Singh, Amar; Mishra, Biswajit; Singh, Nagendra; Sinha, Mau; Dey, Sharmistha; Kaur, Punit; Mitra, Dipendra K; Sharma, Sujata; Singh, Tej P

2011-05-06

Peptidoglycan recognition proteins (PGRPs) are involved in the recognition of pathogen-associated molecular patterns. The well known pathogen-associated molecular patterns include LPS from Gram-negative bacteria and lipoteichoic acid (LTA) from Gram-positive bacteria. In this work, the crystal structures of two complexes of the short form of camel PGRP (CPGRP-S) with LPS and LTA determined at 1.7- and 2.1-Å resolutions, respectively, are reported. Both compounds were held firmly inside the complex formed with four CPGRP-S molecules designated A, B, C, and D. The binding cleft is located at the interface of molecules C and D, which is extendable to the interface of molecules A and C. The interface of molecules A and B is tightly packed, whereas that of molecules B and D forms a wide channel. The hydrophilic moieties of these compounds occupy a common region, whereas hydrophobic chains interact with distinct regions in the binding site. The binding studies showed that CPGRP-S binds to LPS and LTA with affinities of 1.6 × 10(-9) and 2.4 × 10(-8) M, respectively. The flow cytometric studies showed that both LPS- and LTA-induced expression of the proinflammatory cytokines TNF-α and IL-6 was inhibited by CPGRP-S. The results of animal studies using mouse models indicated that both LPS- and LTA-induced mortality rates decreased drastically when CPGRP-S was administered. The recognition of both LPS and LTA, their high binding affinities for CPGRP-S, the significant decrease in the production of LPS- and LTA-induced TNF-α and IL-6, and the drastic reduction in the mortality rates in mice by CPGRP-S indicate its useful properties as an antibiotic agent.

Indirubin Treatment of Lipopolysaccharide-Induced Mastitis in a Mouse Model and Activity in Mouse Mammary Epithelial Cells.

PubMed

Lai, Jin-Lun; Liu, Yu-Hui; Peng, Yong-Chong; Ge, Pan; He, Chen-Fei; Liu, Chang; Chen, Ying-Yu; Guo, Ai-Zhen; Hu, Chang-Min

2017-01-01

Indirubin is a Chinese medicine extracted from indigo and known to be effective for treating chronic myelogenous leukemia, neoplasia, and inflammatory disease. This study evaluated the in vivo anti-inflammatory activity of indirubin in a lipopolysaccharide- (LPS-) induced mouse mastitis model. The indirubin mechanism and targets were evaluated in vitro in mouse mammary epithelial cells. In the mouse model, indirubin significantly attenuated the severity of inflammatory lesions, edema, inflammatory hyperemia, milk stasis and local tissue necrosis, and neutrophil infiltration. Indirubin significantly decreased myeloperoxidase activity and downregulated the production of tumor necrosis factor- α , interleukin-1 β (IL-1 β ), and IL-6 caused by LPS. In vitro, indirubin inhibited LPS-stimulated expression of proinflammatory cytokines in a dose-dependent manner. It also downregulated LPS-induced toll-like receptor 4 (TLR4) expression and inhibited phosphorylation of LPS-induced nuclear transcription factor-kappa B (NF- κ B) P65 protein and inhibitor of kappa B. In addition to its effect on the NF- κ B signaling pathway, indirubin suppressed the mitogen-activated protein kinase (MAPK) signaling by inhibiting phosphorylation of extracellular signal-regulated kinase (ERK), P38, and c-jun NH2-terminal kinase (JNK). Indirubin improved LPS-induced mouse mastitis by suppressing TLR4 and downstream NF- κ B and MAPK pathway inflammatory signals and might be a potential treatment of mastitis and other inflammatory diseases.

Progesterone modulates the LPS-induced nitric oxide production by a progesterone-receptor independent mechanism.

PubMed

Wolfson, Manuel Luis; Schander, Julieta Aylen; Bariani, María Victoria; Correa, Fernando; Franchi, Ana María

2015-12-15

Genital tract infections caused by Gram-negative bacteria induce miscarriage and are one of the most common complications of human pregnancy. LPS administration to 7-day pregnant mice induces embryo resorption after 24h, with nitric oxide playing a fundamental role in this process. We have previously shown that progesterone exerts protective effects on the embryo by modulating the inflammatory reaction triggered by LPS. Here we sought to investigate whether the in vivo administration of progesterone modulated the LPS-induced nitric oxide production from peripheral blood mononuclear cells from pregnant and non-pregnant mice. We found that progesterone downregulated LPS-induced nitric oxide production by a progesterone receptor-independent mechanism. Moreover, our results suggest a possible participation of glucocorticoid receptors in at least some of the anti-inflammatory effects of progesterone. Copyright © 2015 Elsevier B.V. All rights reserved.

The Nuclear Orphan Receptor NR4A1 is Involved in the Apoptotic Pathway Induced by LPS and Simvastatin in RAW 264.7 Macrophages.

PubMed

Kim, Yong Chan; Song, Seok Bean; Lee, Sang Kyu; Park, Sang Min; Kim, Young Sang

2014-04-01

Macrophage death plays a role in several physiological and inflammatory pathologies such as sepsis and arthritis. In our previous work, we showed that simvastatin triggers cell death in LPS-activated RAW 264.7 mouse macrophage cells through both caspase-dependent and independent apoptotic pathways. Here, we show that the nuclear orphan receptor NR4A1 is involved in a caspase-independent apoptotic process induced by LPS and simvastatin. Simvastatin-induced NR4A1 expression in RAW 264.7 macrophages and ectopic expression of a dominant-negative mutant form of NR4A1 effectively suppressed both DNA fragmentation and the disruption of mitochondrial membrane potential (MMP) during LPS- and simvastatin-induced apoptosis. Furthermore, apoptosis was accompanied by Bcl-2-associated X protein (Bax) translocation to the mitochondria. Our findings suggest that NR4A1 expression and mitochondrial translocation of Bax are related to simvastatin-induced apoptosis in LPS-activated RAW 264.7 macrophages.

TLR4-NOX4-AP-1 signaling mediates lipopolysaccharide-induced CXCR6 expression in human aortic smooth muscle cells.

PubMed

Patel, Devang N; Bailey, Steven R; Gresham, John K; Schuchman, David B; Shelhamer, James H; Goldstein, Barry J; Foxwell, Brian M; Stemerman, Michael B; Maranchie, Jodi K; Valente, Anthony J; Mummidi, Srinivas; Chandrasekar, Bysani

2006-09-08

CXCL16 is a transmembrane non-ELR CXC chemokine that signals via CXCR6 to induce aortic smooth muscle cell (ASMC) proliferation. While bacterial lipopolysaccharide (LPS) has been shown to stimulate CXCL16 expression in SMC, its effects on CXCR6 are not known. Here, we demonstrate that LPS upregulates CXCR6 mRNA, protein, and surface expression in human ASMC. Inhibition of TLR4 with neutralizing antibodies or specific siRNA interference blocked LPS-mediated CXCR6 expression. LPS stimulated both AP-1 (c-Fos, c-Jun) and NF-kappaB (p50 and p65) activation, but only inhibition of AP-1 attenuated LPS-induced CXCR6 expression. Using dominant negative expression vectors and siRNA interference, we demonstrate that LPS induces AP-1 activation via MyD88, TRAF6, ERK1/2, and JNK signaling pathways. Furthermore, the flavoprotein inhibitor diphenyleniodonium chloride significantly attenuated LPS-mediated AP-1-dependent CXCR6 expression, as did inhibition of NOX4 NADPH oxidase by siRNA. Finally, CXCR6 knockdown inhibited CXCL16-induced ASMC proliferation. These results demonstrate that LPS-TLR4-NOX4-AP-1 signaling can induce CXCR6 expression in ASMC, and suggest that the CXCL16-CXCR6 axis may be an important proinflammatory pathway in the pathogenesis of atherosclerosis.

TLR4-NOX4-AP-1 signaling mediates lipopolysaccharide-induced CXCR6 expression in human aortic smooth muscle cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Patel, Devang N.; Bailey, Steven R.; Gresham, John K.

2006-09-08

CXCL16 is a transmembrane non-ELR CXC chemokine that signals via CXCR6 to induce aortic smooth muscle cell (ASMC) proliferation. While bacterial lipopolysaccharide (LPS) has been shown to stimulate CXCL16 expression in SMC, its effects on CXCR6 are not known. Here, we demonstrate that LPS upregulates CXCR6 mRNA, protein, and surface expression in human ASMC. Inhibition of TLR4 with neutralizing antibodies or specific siRNA interference blocked LPS-mediated CXCR6 expression. LPS stimulated both AP-1 (c-Fos, c-Jun) and NF-{kappa}B (p50 and p65) activation, but only inhibition of AP-1 attenuated LPS-induced CXCR6 expression. Using dominant negative expression vectors and siRNA interference, we demonstrate thatmore » LPS induces AP-1 activation via MyD88, TRAF6, ERK1/2, and JNK signaling pathways. Furthermore, the flavoprotein inhibitor diphenyleniodonium chloride significantly attenuated LPS-mediated AP-1-dependent CXCR6 expression, as did inhibition of NOX4 NADPH oxidase by siRNA. Finally, CXCR6 knockdown inhibited CXCL16-induced ASMC proliferation. These results demonstrate that LPS-TLR4-NOX4-AP-1 signaling can induce CXCR6 expression in ASMC, and suggest that the CXCL16-CXCR6 axis may be an important proinflammatory pathway in the pathogenesis of atherosclerosis.« less

Whey protein hydrolysates decrease IL-8 secretion in lipopolysaccharide (LPS)-stimulated respiratory epithelial cells by affecting LPS binding to Toll-like receptor 4.

PubMed

Iskandar, Michèle M; Dauletbaev, Nurlan; Kubow, Stan; Mawji, Nadir; Lands, Larry C

2013-07-14

Whey proteins (WP) exert anti-inflammatory and antioxidant effects. Hyperbaric pressurisation of whey increases its digestibility and changes the spectrum of peptides released during digestion. We have shown that dietary supplementation with pressurised whey improves nutritional status and systemic inflammation in patients with cystic fibrosis (CF). Both clinical indices are largely affected by airway processes, to which respiratory epithelial cells actively contribute. Here, we tested whether peptides released from the digestion of pressurised whey can attenuate the inflammatory responses of CF respiratory epithelial cells. Hydrolysates of pressurised WP (pWP) and native WP (nWP, control) were generated in vitro and tested for anti-inflammatory properties judged by the suppression of IL-8 production in CF and non-CF respiratory epithelial cell lines (CFTE29o- and 1HAEo-, respectively). We observed that, in both cell lines, pWP hydrolysate suppressed IL-8 production stimulated by lipopolysaccharide (LPS) to a greater magnitude compared with nWP hydrolysate. Neither hydrolysate suppressed IL-8 production induced by TNF-α or IL-1β, suggesting an effect on the Toll-like receptor (TLR) 4 pathway, the cellular sensor for LPS. Further, neither hydrolysate affected TLR4 expression or neutralised LPS. Both pWP and nWP hydrolysates similarly reduced LPS binding to surface TLR4, while pWP tended to more potently increase extracellular antioxidant capacity. (1) anti-inflammatory properties of whey are enhanced by pressurisation; (2) suppression of IL-8 production may contribute to the clinical effects of pressurised whey supplementation on CF; (3) this effect may be partly explained by a combination of reduced LPS binding to TLR4 and enhanced extracellular antioxidant capacity.

Lipopolysaccharide (LPS) of Porphyromonas gingivalis induces IL-1beta, TNF-alpha and IL-6 production by THP-1 cells in a way different from that of Escherichia coli LPS.

PubMed

Diya Zhang; Lili Chen; Shenglai Li; Zhiyuan Gu; Jie Yan

2008-04-01

Lipopolysaccharide (LPS) derived from the periodontal pathogen Porphyromonas gingivalis has been shown to differ from enterobacterial LPS in structure and function; therefore, the Toll-like receptors (TLRs) and the intracellular inflammatory signaling pathways are accordingly different. To elucidate the signal transduction pathway of P. gingivalis, LPS-induced pro-inflammatory cytokine production in the human monocytic cell line THP-1 was measured by ELISA, and the TLRs were determined by the blocking test using anti-TLRs antibodies. In addition, specific inhibitors as well as Phospho-ELISA kits were used to analyze the intracellular signaling pathways. Escherichia coli LPS was used as the control. In this study, P. gingivalis LPS showed the ability to induce cytokine production in THP-1 cells and its induction was significantly (P < 0.05) suppressed by anti-TLR2 antibody or JNK inhibitor, and the phosphorylation level of JNK was significantly increased (P < 0.05). These results indicate that TLR2-JNK is the main signaling pathway of P. gingivalis LPS-induced cytokine production, while the cytokine induction by E. coli LPS was mainly via TLR4-NF-kappaB and TLR4-p38MAPK. This suggests that P. gingivalis LPS differs from E. coli LPS in its signaling pathway in THP-1 cells, and that the TLR2-JNK pathway might play a significant role in P. gingivalis LPS-induced chronic inflammatory periodontal disease.

TRPM2 contributes to LPS/IFNγ-induced production of nitric oxide via the p38/JNK pathway in microglia.

PubMed

Miyake, Takahito; Shirakawa, Hisashi; Kusano, Ayaka; Sakimoto, Shinya; Konno, Masakazu; Nakagawa, Takayuki; Mori, Yasuo; Kaneko, Shuji

2014-02-07

Microglia are immune cells that maintain brain homeostasis at a resting state by surveying the environment and engulfing debris. However, in some pathological conditions, microglia can produce neurotoxic factors such as pro-inflammatory cytokines and nitric oxide (NO) that lead to neuronal degeneration. Inflammation-induced calcium (Ca(2+)) signaling is thought to underlie this abnormal activation of microglia, but the mechanisms are still obscure. We previously showed that combined application of lipopolysaccharide and interferon γ (LPS/IFNγ) induced-production of NO in microglia from wild-type (WT) mice is significantly reduced in microglia from transient receptor potential melastatin 2 (TRPM2)-knockout (KO) mice. Here, we found that LPS/IFNγ produced a late-onset Ca(2+) signaling in WT microglia, which was abolished by application of the NADPH oxidase inhibitor diphenylene iodonium (DPI) and ML-171. In addition, pharmacological blockade or gene deletion of TRPM2 channel in microglia did not show this Ca(2+) signaling. Furthermore, pharmacological manipulation and Western blotting revealed that Ca(2+) mobilization, the proline-rich tyrosine kinase 2 (Pyk2), p38 mitogen-activated protein kinase (p38 MAPK) and c-Jun NH2-terminal kinase (JNK) contributed to TRPM2-mediated LPS/IFNγ-induced activation, while the extracellular signal-regulated protein kinase (ERK) did not. These results suggest that LPS/IFNγ activates TRPM2-mediated Ca(2+) signaling, which in turn increases downstream p38 MAPK and JNK signaling and results in increased NO production in microglia. Copyright © 2014 Elsevier Inc. All rights reserved.

Sildenafil (Viagra(®)) prevents and restores LPS-induced inflammation in astrocytes.

PubMed

de Santana Nunes, Ana Karolina; Rapôso, Catarina; Björklund, Ulrika; da Cruz-Höfling, Maria Alice; Peixoto, Christina Alves; Hansson, Elisabeth

2016-09-06

Astrocytes are effectively involved in the pathophysiological processes in the central nervous system (CNS) and may contribute to or protect against development of inflammatory and degenerative diseases. Sildenafil is a potent and selective phosphodiesterase-5 (PDE-5) inhibitor, which induces cyclic GMP accumulation. However, the mechanisms of actions on glial cells are not clear. The aim of the present work is to evaluate the role of sildenafil in lipopolysaccharide (LPS)-stimulated astrocytes. The cytoskeleton integrity and Ca(2+) waves were assessed as indicators of inflammatory state. Two main groups were done: (A) one prevention and (B) one restoration. Each of these groups: A1: control; A2: LPS for 24h; A3: sildenafil 1 or 10μM for 4h and then sildenafil 1 or 10μM+LPS for 24h. B1: control; B2: LPS for 24h; B3: LPS for 24h and then LPS+sildenafil 1 or 10μM for 24h. Cytoskeleton integrity was analyzed through GFAP immunolabeling and actin labeling with an Alexa 488-conjugated phalloidin probe. Calcium responses were assessed through a Ca(2+)-sensitive fluorophore Fura-2/AM. The results show that both preventive and restorative treatments with sildenafil (in both concentrations) reduced the Ca(2+) responses in intensity and induced a more organized actin fiber pattern, compared to LPS treated cells. This work demonstrated for the first time that astrocytes are a key part of the sildenafil protective effects in the CNS. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Electroconvulsive seizures (ECS) do not prevent LPS-induced behavioral alterations and microglial activation.

PubMed

van Buel, E M; Bosker, F J; van Drunen, J; Strijker, J; Douwenga, W; Klein, H C; Eisel, U L M

2015-12-12

Long-term neuroimmune activation is a common finding in major depressive disorder (MDD). Literature suggests a dual effect of electroconvulsive therapy (ECT), a highly effective treatment strategy for MDD, on neuroimmune parameters: while ECT acutely increases inflammatory parameters, such as serum levels of pro-inflammatory cytokines, there is evidence to suggest that repeated ECT sessions eventually result in downregulation of the inflammatory response. We hypothesized that this might be due to ECT-induced attenuation of microglial activity upon inflammatory stimuli in the brain. Adult male C57Bl/6J mice received a series of ten electroconvulsive seizures (ECS) or sham shocks, followed by an intracerebroventricular (i.c.v.) lipopolysaccharide (LPS) or phosphate-buffered saline (PBS) injection. Brains were extracted and immunohistochemically stained for the microglial marker ionized calcium-binding adaptor molecule 1 (Iba1). In addition, a sucrose preference test and an open-field test were performed to quantify behavioral alterations. LPS induced a short-term reduction in sucrose preference, which normalized within 3 days. In addition, LPS reduced the distance walked in the open field and induced alterations in grooming and rearing behavior. ECS did not affect any of these parameters. Phenotypical analysis of microglia demonstrated an LPS-induced increase in microglial activity ranging from 84 to 213 % in different hippocampal regions (CA3 213 %; CA1 84 %; dentate gyrus 131 %; and hilus 123 %). ECS-induced alterations in microglial activity were insignificant, ranging from -2.6 to 14.3 % in PBS-injected mice and from -20.2 to 6.6 % in LPS-injected mice. We were unable to demonstrate an effect of ECS on LPS-induced microglial activity or behavioral alterations.

Lipopolysaccharide-induced inhibition of transcription of tlr4 in vitro is reversed by dexamethasone and correlates with presence of conserved NFκB binding sites

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bonin, Camila P., E-mail: mila_bonin@yahoo.com.br; Baccarin, Raquel Y.A., E-mail: baccarin@usp.br; Nostell, Katarina, E-mail: katarina.nostell@slu.se

2013-03-08

Highlights: ► Chimpanzees, horses and humans have regions of similarity on TLR4 and MD2 promoters. ► Rodents have few regions of similarity on TLR4 promoter when compared to primates. ► Conserved NFkB binding sites were found in the promoters of TLR4 and MD2. ► LPS-induced inhibition of TLR4 transcription is reversed by dexamethasone. ► LPS-induced transcription of MD2 is inhibited by dexamethasone. -- Abstract: Engagement of Toll-like receptor 4 (TLR4) by lipopolysaccharide (LPS) is a master trigger of the deleterious effects of septic shock. Horses and humans are considered the most sensitive species to septic shock, but the mechanisms explainingmore » these phenomena remain elusive. Analysis of tlr4 promoters revealed high similarity among LPS-sensitive species (human, chimpanzee, and horse) and low similarity with LPS-resistant species (mouse and rat). Four conserved nuclear factor kappa B (NFκB) binding sites were found in the tlr4 promoter and two in the md2 promoter sequences that are likely to be targets for dexamethasone regulation. In vitro treatment of equine peripheral blood mononuclear cells (eqPBMC) with LPS decreased transcripts of tlr4 and increased transcription of md2 (myeloid differentiation factor 2) and cd14 (cluster of differentiation 14). Treatment with dexamethasone rescued transcription of tlr4 after LPS inhibition. LPS-induced transcription of md2 was inhibited in the presence of dexamethasone. Dexamethasone alone did not affect transcription of tlr4 and md2.« less

Aloe vera downregulates LPS-induced inflammatory cytokine production and expression of NLRP3 inflammasome in human macrophages.

PubMed

Budai, Marietta M; Varga, Aliz; Milesz, Sándor; Tőzsér, József; Benkő, Szilvia

2013-12-01

Aloe vera has been used in traditional herbal medicine as an immunomodulatory agent inducing anti-inflammatory effects. However, its role on the IL-1β inflammatory cytokine production has not been studied. IL-1β production is strictly regulated both at transcriptional and posttranslational levels through the activity of Nlrp3 inflammasome. In this study we aimed to determine the effect of Aloe vera on the molecular mechanisms of Nlrp3 inflammasome-mediated IL-1β production in LPS-activated human THP-1 cells and monocyte-derived macrophages. Our results show that Aloe vera significantly reduced IL-8, TNFα, IL-6 and IL-1β cytokine production in a dose dependent manner. The inhibitory effect was substantially more pronounced in the primary cells. We found that Aloe vera inhibited the expression of pro-IL-1β, Nlrp3, caspase-1 as well as that of the P2X7 receptor in the LPS-induced primary macrophages. Furthermore, LPS-induced activation of signaling pathways like NF-κB, p38, JNK and ERK were inhibited by Aloe vera in these cells. Altogether, we show for the first time that Aloe vera-mediated strong reduction of IL-1β appears to be the consequence of the reduced expression of both pro-IL-1β as well as Nlrp3 inflammasome components via suppressing specific signal transduction pathways. Furthermore, we show that the expression of the ATP sensor P2X7 receptor is also downregulated by Aloe vera that could also contribute to the attenuated IL-1β cytokine secretion. These results may provide a new therapeutic approach to regulate inflammasome-mediated responses. Copyright © 2013 Elsevier Ltd. All rights reserved.

Inhibition of nitric oxide synthase abrogates lipopolysaccharides-induced up-regulation of L-arginine uptake in rat alveolar macrophages

PubMed Central

Hammermann, Rainer; Stichnote, Christina; Closs, Ellen Ildicho; Nawrath, Hermann; Racké, Kurt

2001-01-01

It was tested whether the inducible nitric oxide synthase (iNOS) pathway might be involved in lipopolysaccharides-(LPS)-induced up-regulation of L-arginine transport in rat alveolar macrophages (AMΦ). AMΦ were cultured in absence or presence of LPS. Nitrite accumulation was determined in culture media and cells were used to study [3H]-L-arginine uptake or to isolate RNA for RT – PCR. Culture in presence of LPS (1 μg ml−1, 20 h) caused 11 fold increase of nitrite accumulation and 2.5 fold increase of [3H]-L-arginine uptake. The inducible NO synthase (iNOS) inhibitor 2-amino-5,6-dihydro-6-methyl-4H-1,3-thiazine (AMT) present alone during culture had only marginal effects on [3H]-L-arginine uptake. However, AMT present during culture additionally to LPS, suppressed LPS-induced nitrite accumulation and LPS-stimulated [3H]-L-arginine uptake in the same concentration-dependent manner. AMT present only for the last 30 min of the culture period had similar effects on [3H]-L-arginine uptake. AMT present only during the uptake period also inhibited LPS-stimulated [3H]-L-arginine uptake, but with lower potency. The inhibitory effect of AMT could not be opposed by the NO releasing compound DETA NONOate. LPS caused an up-regulation of the mRNA for the cationic amino acid transporter CAT-2B, and this effect was not affected by AMT. AMT (100 μM) did not affect L-arginine transport studied by electrophysiological techniques in Xenopus laevis oocytes expressing either the human cationic amino acid transporter hCAT-1 or hCAT-2B. In conclusion, iNOS inhibition in rat AMΦ abolished LPS-activated L-arginine uptake. This effect appears to be caused by reduced flow of L-arginine through the iNOS pathway. PMID:11375254

LPS-induced systemic inflammation reveals an immunomodulatory role for the prion protein at the blood-brain interface.

PubMed

Salvesen, Ø; Reiten, M R; Espenes, A; Bakkebø, M K; Tranulis, M A; Ersdal, C

2017-05-22

The cellular prion protein (PrP C ) is an evolutionary conserved protein abundantly expressed not only in the central nervous system but also peripherally including the immune system. A line of Norwegian dairy goats naturally devoid of PrP C (PRNP Ter/Ter ) provides a novel model for studying PrP C physiology. In order to explore putative roles for PrP C in acute inflammatory responses, we performed a lipopolysaccharide (LPS, Escherichia coli O26:B6) challenge of 16 goats (8 PRNP +/+ and 8 PRNP Ter/Ter ) and included 10 saline-treated controls (5 of each PRNP genotype). Clinical examinations were performed continuously, and blood samples were collected throughout the trial. Genome-wide transcription profiles of the choroid plexus, which is at the blood-brain interface, and the hippocampus were analyzed by RNA sequencing, and the same tissues were histologically evaluated. All LPS-treated goats displayed clinical signs of sickness behavior, which were of significantly (p < 0.01) longer duration in animals without PrP C . In the choroid plexus, a substantial alteration of the transcriptome and activation of Iba1-positive cells were observed. This response included genotype-dependent differential expression of several genes associated with the immune response, such as ISG15, CXCL12, CXCL14, and acute phase proteins, among others. Activation of cytokine-responsive genes was skewed towards a more profound type I interferon response, and a less obvious type II response, in PrP C -deficient goats. The magnitude of gene expression in response to LPS was smaller in the hippocampus than in the choroid plexus. Resting state expression profiles revealed a few differences between the PRNP genotypes. Our data suggest that PrP C acts as a modulator of certain pathways of innate immunity signaling, particularly downstream of interferons, and probably contributes to protection of vulnerable tissues against inflammatory damage.

Enhanced LPS-induced activation of IL-27 signalling in sarcoidosis.

PubMed

Ringkowski, Sabine; Loke, Joshua; Huang, Shuying; Ahmadzai, Hasib; Herth, Felix J F; Thomas, Paul S; Herbert, Cristan

2016-08-01

Granulomas in sarcoidosis have recently been described as containing Interleukin (IL)-27, one of the members of the IL-12 family of cytokines, which also includes IL-35. Levels of these cytokines and the IL-27 receptor subunits were hypothesised to differ between patients with sarcoidosis compared to healthy controls in peripheral blood. Using a cross-sectional study design, plasma and peripheral blood mononuclear cells (PBMC) were collected from patients and control subjects. Protein and mRNA (in PBMC) levels for IL-27 and IL-35 (IL27, EBI3, IL12A subunits) as well as IL-27 receptor (IL6ST and IL27RA subunits) were assessed spontaneously and following direct (LPS) and indirect (anti-CD3/28 activation beads) macrophage stimulation using RT- PCR, ELISA and flow cytometry. Following stimulation with LPS, PBMC of patients with sarcoidosis displayed significantly enhanced expression of IL27 and EBI3 mRNA (p = 0.020 and p = 0.037 respectively) compared to PBMCs from healthy controls. There was also significantly enhanced production of IL-27 by PBMC from patients with sarcoidosis compared to healthy controls in response to LPS stimulation (p = 0.027). IL6ST mRNA and IL6ST protein were significantly lower in patients with sarcoidosis (mRNA p = 0.0002; MFI p = 0.0015) whilst IL27RA protein levels were significantly higher in patients with sarcoidosis compared to healthy controls (MFI p < 0.0001). Plasma IL-35 protein levels did not differ between control and sarcoidosis subjects (p = 0.23). These results suggest there may be exaggerated activation of IL-27 signalling in response to LPS in sarcoidosis. Copyright © 2016 Elsevier Ltd. All rights reserved.

Taraxacum officinale Weber extracts inhibit LPS-induced oxidative stress and nitric oxide production via the NF-κB modulation in RAW 264.7 cells.

PubMed

Park, Chung Mu; Park, Ji Young; Noh, Kyung Hee; Shin, Jin Hyuk; Song, Young Sun

2011-01-27

The common dandelion (Taraxacum officinale G.H. Weber ex Wiggers, Asteraceae) has been widely used in folklore medicine to treat dyspepsia, heartburn, and spleen and liver disorders. To compare the antioxidative and anti-inflammatory activities of Taraxacum officinale methanol extract (TOME) and water extract (TOWE) in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells and assess their constitutional differences, including luteolin, chicoric acid, and total phenol content. Antioxidative enzyme activities, nitric oxide (NO) production, and inducible NO synthase (iNOS) and nuclear factor (NF)-κB expression were estimated by biochemical analysis, the Griess reaction, reverse transcription-polymerase chain reaction, western hybridization, and electrophoretic mobility shift assay. High-performance liquid chromatography and the Folin-Ciocalteau method were used to analyze functional phytochemicals and total phenol content. TOME and TOWE significantly reduced NO production with an IC(50) of 79.9 and 157.5 μg/mL, respectively, without cytotoxicity. Depleted glutathione (GSH) and antioxidative enzyme activities, including superoxide dismutase, catalase, GSH-peroxidase, and GSH-reductase, were restored by dandelion extracts. Both extracts inhibited LPS-stimulated iNOS gene expression and that of its transcription factor, NF-κB, in parallel with nitrite reduction. TOME showed more potent antioxidative and anti-inflammatory capacities than TOWE, which was attributable to its high total phenol, luteolin, and chicoric acid content. These results indicate that TOME and TOWE inhibit oxidative stress and inflammatory responses through elevated de novo synthesis of antioxidative enzymes and suppression of iNOS expression by NF-κB inactivation. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

Pleurotus giganteus (Berk. Karun & Hyde), the giant oyster mushroom inhibits NO production in LPS/H2O2 stimulated RAW 264.7 cells via STAT 3 and COX-2 pathways.

PubMed

Baskaran, Asweni; Chua, Kek Heng; Sabaratnam, Vikineswary; Ravishankar Ram, Mani; Kuppusamy, Umah Rani

2017-01-13

Pleurotus giganteus (Berk. Karunarathna and K.D. Hyde), has been used as a culinary mushroom and is known to have medicinal properties but its potential as an anti-inflammatory agent to mitigate inflammation triggered diseases is untapped. In this study, the molecular mechanism underlying the protective effect of ethanol extract of P. giganteus (EPG) against lipopolysaccharide (LPS) and combination of LPS and hydrogen peroxide (H 2 O 2 )-induced inflammation on RAW 264.7 macrophages was investigated. The effect of EPG on nitric oxide (NO) production as an indicator of inflammation in RAW 264.7 macrophages was estimated based on Griess reaction that measures nitrite level. The expressions of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), NF-kB activating protein (NKAP), signal transducer and activator of transcription 3 protein (STAT 3) and glutathione peroxidase (GPx) genes were assessed using real time reverse transcription polymerase chain reaction (RT-PCR) approach. EPG (10 μg/ml) showed the highest reduction in the LPS-induced NO production in RAW 264.7 macrophages and significantly suppressed (p < 0.05) the expression iNOS, STAT 3 and COX-2. There was a significant increase (p < 0.05) in combination of LPS and H 2 O 2 - induced iNOS production when compared to the LPS-induced iNOS production in RAW 264.7 macrophages and this concurred with the NO production which was attenuated by EPG at 10 μg/ml. A significant (p < 0.05) down regulation was observed in the combination of LPS and H 2 O 2 -induced iNOS and GPx expression by EPG. Our data suggest that the anti-inflammatory activity of EPG is mediated via the suppression of the STAT 3 and COX-2 pathways and can serve as potential endogenous antioxidant stimulant.

Tocotrienols inhibit lipopolysaccharide-induced pro-inflammatory cytokines in macrophages of female mice

PubMed Central

2010-01-01

Background Inflammation has been implicated in cardiovascular disease, and the important role of proteasomes in the development of inflammation and other macrophage functions has been demonstrated. Tocotrienols are potent hypocholesterolemic agents that inhibit β-hydroxy-β-methylglutaryl coenzyme A reductase activity, which is degraded via the ubiquitin-proteasome pathway. Our objective was to evaluate the effect of tocotrienols in reducing inflammation. Lipopolysaccharide (LPS) was used as a prototype for inflammation in murine RAW 264.7 cells and BALB/c female mice. Results The present results clearly demonstrate that α-, γ-, or δ-tocotrienol treatments inhibit the chymotrypsin-like activity of 20 S rabbit muscle proteasomes (> 50%; P < 0.05). Chymotrypsin, trypsin, and post-glutamase activities were decreased > 40% (P < 0.05) with low concentrations (< 80 μM), and then increased gradually with concentrations of (80 - 640 μM) in RAW 264.7 whole cells. Tocotrienols showed 9 - 33% (P < 0.05) inhibitions in TNF-α secretion in LPS-stimulated RAW 264.7 cells. Results of experiments carried out in BALB/c mice demonstrated that serum levels of TNF-α after LPS treatment were also reduced (20 - 48%; P < 0.05) by tocotrienols with doses of 1 and 10 μg/kg, and a corresponding rise in serum levels of corticosterone (19 - 41%; P < 0.05) and adrenocorticotropic hormone (81 - 145%; P < 0.02) was observed at higher concentrations (40 μM). Maximal inhibition of LPS-induced TNF-α was obtained with δ-tocotrienol (10 μg/kg). Low concentrations of δ-Tocotrienols (< 20 μM) blocked LPS-induced gene expression of TNF-α, IL-1β, IL-6 and iNOS (> 40%), while higher concentrations (40 μM) increased gene expression of the latter in peritoneal macrophages (prepared from BALB/c mice) as compared to control group. Conclusions These results represent a novel approach by using natural products, such as tocotrienols as proteasome modulators, which may lead to the development of

Losartan attenuated lipopolysaccharide-induced lung injury by suppression of lectin-like oxidized low-density lipoprotein receptor-1.

PubMed

Deng, Wang; Deng, Yue; Deng, Jia; Wang, Dao-Xin; Zhang, Ting

2015-01-01

Recent study has shown that renin-angiotensin system plays an important role in the development of acute lung injury (ALI) with high level of angiotensin II (AngII) generated form AngI catalyzed by angiotensin-converting enzyme. AngII plays a major effect mainly through AT1 receptor. Therefore, we speculate inhibition of AT1 receptor may possibly attenuate the lung injury. Losartan, an antagonist of AT1 receptor for angiotensin II, attenuated lung injury by alleviation of the inflammation response in ALI, but the mechanism of losartan in ALI still remains unclear. Thirty male Sprague-Dawley rats were randomly divided into Control group, ALI group (LPS), and Losartan group (LPS + Losartan). Bronchoalveolar lavage fluid (BALF) and lung tissue were obtained for analysis. The expressions of lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1), intercellular adhesion molecule-1 (ICAM-1) and caspase-3 were detected by reverse transcriptase polymerase chain reaction (RT-PCR) and western blotting. In ALI group, TNF-α and protein level in BALF, MPO activity in lung tissue, pulmonary edema and lung injury were significantly increased. Losartan significantly reduced LPS-induced increase in TNF-α and protein level in BALF, MPO activity, pulmonary edema and lung injury in LPS-induced lung injury. The mRNA and protein expression levels of LOX-1 were significantly decreased with the administration of losartan in LPS-induced lung injury. Also, losartan blocked the protein levels of caspase-3 and ICAM-1 mediated by LOX-1 in LPS-induced lung injury. Losartan attenuated lung injury by alleviation of the inflammation and cell apoptosis by inhibition of LOX-1 in LPS-induced lung injury.

Losartan attenuated lipopolysaccharide-induced lung injury by suppression of lectin-like oxidized low-density lipoprotein receptor-1

PubMed Central

Deng, Wang; Deng, Yue; Deng, Jia; Wang, Dao-Xin; Zhang, Ting

2015-01-01

Introduction: Recent study has shown that renin-angiotensin system plays an important role in the development of acute lung injury (ALI) with high level of angiotensin II (AngII) generated form AngI catalyzed by angiotensin-converting enzyme. AngII plays a major effect mainly through AT1 receptor. Therefore, we speculate inhibition of AT1 receptor may possibly attenuate the lung injury. Losartan, an antagonist of AT1 receptor for angiotensin II, attenuated lung injury by alleviation of the inflammation response in ALI, but the mechanism of losartan in ALI still remains unclear. Methods: Thirty male Sprague-Dawley rats were randomly divided into Control group, ALI group (LPS), and Losartan group (LPS + Losartan). Bronchoalveolar lavage fluid (BALF) and lung tissue were obtained for analysis. The expressions of lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1), intercellular adhesion molecule-1 (ICAM-1) and caspase-3 were detected by reverse transcriptase polymerase chain reaction (RT-PCR) and western blotting. Results: In ALI group, TNF-α and protein level in BALF, MPO activity in lung tissue, pulmonary edema and lung injury were significantly increased. Losartan significantly reduced LPS-induced increase in TNF-α and protein level in BALF, MPO activity, pulmonary edema and lung injury in LPS-induced lung injury. The mRNA and protein expression levels of LOX-1 were significantly decreased with the administration of losartan in LPS-induced lung injury. Also, losartan blocked the protein levels of caspase-3 and ICAM-1 mediated by LOX-1 in LPS-induced lung injury. Conclusions: Losartan attenuated lung injury by alleviation of the inflammation and cell apoptosis by inhibition of LOX-1 in LPS-induced lung injury. PMID:26884836

α-Dihydroxychalcone-glycoside (α-DHC) isolated from the heartwood of Pterocarpus marsupium inhibits LPS induced MAPK activation and up regulates HO-1 expression in murine RAW 264.7 macrophage

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chakraborty, Prarthana; Saraswat, Ghungroo; Kabir, Syed N., E-mail: snkabir@iicb.res.in

2014-05-15

Three phenolic glycosides isolated from the heartwood of Pterocarpus marsupium showed significant free radical and superoxide ion scavenging activity and antioxidant potential that were comparable to, or several folds higher than those of standard antioxidants, trolox and ascorbic acid. The effective concentrations of these compounds were far below their cytotoxic levels. Compound 3, which was characterized to be α-dihydroxychalcone-glycoside (α-DHC), was the most potent one. Subsequent studies demonstrated that α-DHC effectively reduced nitric oxide and cytokine production by the LPS stimulated RAW 264.7 mouse macrophage cell line. The compound effectively attenuated the expression of inflammation-mediating enzymes COX-2 and iNOS atmore » the mRNA as well as protein levels in a concentration dependent manner. It prevented phosphorylation of all the three MAPKs (JNK, ERK, p38) and eventually blocked the activation of downstream elements contributing to inflammation. Phosphorylation of IκB-α and subsequent translocation of NF-κB into the nucleus were restricted, while the expression of stress responsive gene HO-1 was up-regulated. α-DHC targeted Keap-1 by modifying its cysteine thiols, dissociating it from Nrf-2 and facilitating nuclear entry of the latter; and this in turn induced HO-1 expression. Thus α-DHC exerts its anti-inflammatory activity in a dual manner: by down regulating MAPKs and restricting nuclear stabilization of NF-κB at one end, and by disrupting Nrf-2–Keap-1 complex on the other. In conclusion, the anti-inflammatory potential together with its high therapeutic index envisages α-DHC as a prospective candidate molecule for the development of therapeutic strategy against inflammatory disorders. - Highlights: • α-DHC isolated from Pterocarpus marsupium has significant antioxidant potential. • α-DHC inhibits NO, IL-6, IL-1β, TNF-α production in LPS-stimulated RAW 264.7 cells. • α-DHC down-regulates of COX-2, iNOS expression in

C-Reactive Protein (CRP), Interferon Gamma-Inducible Protein 10 (IP-10), and Lipopolysaccharide (LPS) Are Associated with Risk of Tuberculosis after Initiation of Antiretroviral Therapy in Resource-Limited Settings

PubMed Central

Tenforde, Mark W.; Gupte, Nikhil; Dowdy, David W.; Asmuth, David M.; Balagopal, Ashwin; Pollard, Richard B.; Sugandhavesa, Patcharaphan; Lama, Javier R.; Pillay, Sandy; Cardoso, Sandra W.; Pawar, Jyoti; Santos, Breno; Riviere, Cynthia; Mwelase, Noluthando; Kanyama, Cecilia; Kumwenda, Johnstone; Hakim, James G.; Kumarasamy, Nagalingeswaran; Bollinger, Robert; Semba, Richard D.; Campbell, Thomas B.; Gupta, Amita

2015-01-01

Objective The association between pre-antiretroviral (ART) inflammation and immune activation and risk for incident tuberculosis (TB) after ART initiation among adults is uncertain. Design Nested case-control study (n = 332) within ACTG PEARLS trial of three ART regimens among 1571 HIV-infected, treatment-naïve adults in 9 countries. We compared cases (participants with incident TB diagnosed by 96 weeks) to a random sample of controls (participants who did not develop TB, stratified by country and treatment arm). Methods We measured pre-ART C-reactive protein (CRP), EndoCab IgM, ferritin, interferon gamma (IFN-γ), interleukin 6 (IL-6), interferon gamma-inducible protein 10 (IP-10), lipopolysaccharide (LPS), soluble CD14 (sCD14), tumor necrosis factor alpha (TNF-α), and CD4/DR+/38+ and CD8/DR+/38+ T cells. Markers were defined according to established cutoff definitions when available, 75th percentile of measured values when not, and detectable versus undetectable for LPS. Using logistic regression, we measured associations between biomarkers and incident TB, adjusting for age, sex, study site, treatment arm, baseline CD4 and log10 viral load. We assessed the discriminatory value of biomarkers using receiver operating characteristic (ROC) analysis. Results Seventy-seven persons (4.9%) developed incident TB during follow-up. Elevated baseline CRP (aOR 3.25, 95% CI: 1.55–6.81) and IP-10 (aOR 1.89, 95% CI: 1.05–3.39), detectable plasma LPS (aOR 2.39, 95% CI: 1.13–5.06), and the established TB risk factors anemia and hypoalbuminemia were independently associated with incident TB. In ROC analysis, CRP, albumin, and LPS improved discrimination only modestly for TB risk when added to baseline routine patient characteristics including CD4 count, body mass index, and prior TB. Conclusion Incident TB occurs commonly after ART initiation. Although associated with higher post-ART TB risk, baseline CRP, IP-10, and LPS add limited value to routine patient characteristics

Evidence that N-acetylcysteine inhibits TNF-alpha-induced cerebrovascular endothelin-1 upregulation via inhibition of mitogen- and stress-activated protein kinase.

PubMed

Sury, Matthias D; Frese-Schaper, Manuela; Mühlemann, Miranda K; Schulthess, Fabienne T; Blasig, Ingolf E; Täuber, Martin G; Shaw, Sidney G; Christen, Stephan

2006-11-01

N-acetylcysteine (NAC) is neuroprotective in animal models of acute brain injury such as caused by bacterial meningitis. However, the mechanism(s) by which NAC exerts neuroprotection is unclear. Gene expression of endothelin-1 (ET-1), which contributes to cerebral blood flow decline in acute brain injury, is partially regulated by reactive oxygen species, and thus a potential target of NAC. We therefore examined the effect of NAC on tumor necrosis factor (TNF)-alpha-induced ET-1 production in cerebrovascular endothelial cells. NAC dose dependently inhibited TNF-alpha-induced preproET-1 mRNA upregulation and ET-1 protein secretion, while upregulation of inducible nitric oxide synthase (iNOS) was unaffected. Intriguingly, NAC had no effect on the initial activation (i.e., IkappaB degradation, nuclear p65 translocation, and Ser536 phosphorylation) of NF-kappaB by TNF-alpha. However, transient inhibition of NF-kappaB DNA binding suggested that NAC may inhibit ET-1 upregulation by inhibiting (a) parallel pathway(s) necessary for full transcriptional activation of NF-kappaB-mediated ET-1 gene expression. Similar to NAC, the MEK1/2 inhibitor U0126, the p38 inhibitor SB203580, and the protein kinase inhibitor H-89 selectively inhibited ET-1 upregulation without affecting nuclear p65 translocation, suggesting that NAC inhibits ET-1 upregulation via inhibition of mitogen- and stress-activated protein kinase (MSK). Supporting this notion, cotreatment with NAC inhibited the TNF-alpha-induced rise in MSK1 and MSK2 kinase activity, while siRNA knock-down experiments showed that MSK2 is the predominant isoform involved in TNF-alpha-induced ET-1 upregulation.

Synthesis and optimization of novel allylated mono-carbonyl analogs of curcumin (MACs) act as potent anti-inflammatory agents against LPS-induced acute lung injury (ALI) in rats.

PubMed

Zhu, Heping; Xu, Tingting; Qiu, Chenyu; Wu, Beibei; Zhang, Yali; Chen, Lingfeng; Xia, Qinqin; Li, Chenglong; Zhou, Bin; Liu, Zhiguo; Liang, Guang

2016-10-04

A series of novel symmetric and asymmetric allylated mono-carbonyl analogs of curcumin (MACs) were synthesized using an appropriate synthetic route and evaluated experimentally thru the LPS-induced expression of TNF-α and IL-6. Most of the obtained compounds exhibited improved water solubility as a hydrochloride salt compared to lead molecule 8f. The most active compound 7a was effective in reducing the Wet/Dry ratio in the lungs and protein concentration in bronchoalveolar lavage fluid. Meanwhile, 7a also inhibited mRNA expression of several inflammatory cytokines, including TNF-α, IL-6, IL-1β, and VCAM-1, in Beas-2B cells after Lipopolysaccharide (LPS) challenge. These results suggest that 7a could be therapeutically beneficial for use as an anti-inflammatory agent in the clinical treatment of acute lung injury (ALI). Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Anti-inflammatory effects of physalin E from Physalis angulata on lipopolysaccharide-stimulated RAW 264.7 cells through inhibition of NF-κB pathway.

PubMed

Yang, Yan-Jun; Yi, Lang; Wang, Qing; Xie, Bing-Bing; Dong, Yan; Sha, Cong-Wei

2017-04-01

Physalin E is a naturally occurring seco-steroid isolated from the stems and aerial parts of Physalis angulata L. (Solanaceae). This study was aimed to explore the anti-inflammatory effects of physalin E on RAW 264.7 mouse macrophages stimulated by lipopolysaccharide (LPS) and the potential underlying mechanisms. The results showed that physalin E significantly inhibited LPS-induced tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) expression and secretion in a dose-dependent manner. Unlike dexamethasone, these effects could not be blocked by miferstone (RU486). Meanwhile, physalin E reduced the degradation of I-kappa B protein in the cytoplasm and downregulated the nuclear factor-κB (NF-κB) p65 protein in the nuclear, which resulted in the inhibition of the NF-κB nuclear translocation. In conclusion, physalin E exerts its anti-inflammatory activities in LPS-induced macrophages. Physalin E can inhibit the production of inflammatory cytokines by targeting the NF-κB signaling pathway.

Anacardic acid, a histone acetyltransferase inhibitor, modulates LPS-induced IL-8 expression in a human alveolar epithelial cell line A549

PubMed Central

Takizawa, Hajime

2013-01-01

Objective and design: The histone acetylation processes, which are believed to play a critical role in the regulation of many inflammatory genes, are reversible and regulated by histone acetyltransferases (HATs), which promote acetylation, and histone deacetylases (HDACs), which promote deacetylation. We studied the effects of lipopolysaccharide (LPS) on histone acetylation and its role in the regulation of interleukin (IL)-8 expression.  Material: A human alveolar epithelial cell line A549 was used in vitro. Methods: Histone H4 acetylation at the IL-8 promoter region was assessed by a chromatin immunoprecipitation (ChIP) assay. The expression and production of IL-8 were evaluated by quantitative polymerase chain reaction and specific immunoassay. Effects of a HDAC inhibitor, trichostatin A (TSA), and a HAT inhibitor, anacardic acid, were assessed.  Results: Escherichia coli-derived LPS showed a dose- and time-dependent stimulatory effect on IL-8 protein production and mRNA expression in A549 cells in vitro. LPS showed a significant stimulatory effect on histone H4 acetylation at the IL-8 promoter region by ChIP assay. Pretreatment with TSA showed a dose-dependent stimulatory effect on IL-8 release from A549 cells as compared to LPS alone. Conversely, pretreatment with anacardic acid inhibited IL-8 production and expression in A549 cells.  Conclusion: These data suggest that LPS-mediated proinflammatory responses in the lungs might be modulated via changing chromatin remodeling by HAT inhibition. PMID:24627774

[Autophagy modulates the levels of inflammatory cytokines in macrophages induced by lipopolysaccharide].

PubMed

Ren, Caiyuan; Zhang, Xiangying; Shi, Hongbo; Chen, Dexi; Duan, Zhongping; Zhang, Huanhu; Ren, Feng

2017-05-01

Objective To analyze the effect of autophagy on inflammatory response in macrophages induced by lipopolysaccharide (LPS) and investigate its molecular mechanism. Methods Bone marrow mesenchymal stem cells, which were separated from the femora of mice, were cultured and induced to differentiate into primary macrophages in vitro. The inflammatory cell model was established by stimulating the primary macrophages with LPS. Autophagy was inhibited by 3-methyladenine (3-MA) or promoted by rapamycin. Green fluorescent protein-microtubule associated protein 1 light chain 3 (GFP-LC3) plasmid was used to transfect primary macrophages and the percentage of cells with GFP-LC3 puncta were counted in the different groups. The mRNA levels of LC3B, tumor necrosis factor α (TNF-α), interleukin 1β (IL-1β), IL-6 and IL-12p40 were detected by real-time quantitative PCR, and the protein levels of LC3B, nuclear factor κB (NF-κB) and IκBα were determined by Western blotting. Results LC3B mRNA and protein expression levels were gradually up-regulated and the autophagosomes increased in the macrophages 2, 4 and 6 hours after treated by LPS. Compared with only LPS treatment group, autophagy inhibition by 3-MA pretreatment promoted the mRNA expressions of inflammatory cytokines including TNF-α, IL-1β, IL-6 and IL-12p40, and the autophagy induction by rapamycin pretreatment suppressed TNF-α, IL-1β, IL-6 and IL-12p40. Meanwhile, 3-MA or rapamycin pretreatment further regulated the protein expressions of IκBα and p-NF-kBp65 induced by LPS in macrophages. Conclusion Autophagy can suppress the LPS-induced inflammatory response in macrophages by regulating NF-κB signaling pathway.

Vildagliptin ameliorates pulmonary fibrosis in lipopolysaccharide-induced lung injury by inhibiting endothelial-to-mesenchymal transition.

PubMed

Suzuki, Toshio; Tada, Yuji; Gladson, Santhi; Nishimura, Rintaro; Shimomura, Iwao; Karasawa, Satoshi; Tatsumi, Koichiro; West, James

2017-10-16

Pulmonary fibrosis is a late manifestation of acute respiratory distress syndrome (ARDS). Sepsis is a major cause of ARDS, and its pathogenesis includes endotoxin-induced vascular injury. Recently, endothelial-to-mesenchymal transition (EndMT) was shown to play an important role in pulmonary fibrosis. On the other hand, dipeptidyl peptidase (DPP)-4 was reported to improve vascular dysfunction in an experimental sepsis model, although whether DPP-4 affects EndMT and fibrosis initiation during lipopolysaccharide (LPS)-induced lung injury is unclear. The aim of this study was to investigate the anti-EndMT effects of the DPP-4 inhibitor vildagliptin in pulmonary fibrosis after systemic endotoxemic injury. A septic lung injury model was established by intraperitoneal injection of lipopolysaccharide (LPS) in eight-week-old male mice (5 mg/kg for five consecutive days). The mice were then treated with vehicle or vildagliptin (intraperitoneally, 10 mg/kg, once daily for 14 consecutive days from 1 day before the first administration of LPS.). Flow cytometry, immunohistochemical staining, and quantitative polymerase chain reaction (qPCR) analysis was used to assess cell dynamics and EndMT function in lung samples from the mice. Lung tissue samples from treated mice revealed obvious inflammatory reactions and typical interstitial fibrosis 2 days and 28 days after LPS challenge. Quantitative flow cytometric analysis showed that the number of pulmonary vascular endothelial cells (PVECs) expressing alpha-smooth muscle actin (α-SMA) or S100 calcium-binding protein A4 (S100A4) increased 28 days after LPS challenge. Similar increases in expression were also confirmed by qPCR of mRNA from isolated PVECs. EndMT cells had higher proliferative activity and migration activity than mesenchymal cells. All of these changes were alleviated by intraperitoneal injection of vildagliptin. Interestingly, vildagliptin and linagliptin significantly attenuated EndMT in the absence of immune

A novel imidazopyridine derivative, X22, attenuates sepsis-induced lung and liver injury by inhibiting the inflammatory response in vitro and in vivo

PubMed Central

Ge, Xiangting; Feng, Zhiguo; Xu, Tingting; Wu, Beibei; Chen, Hongjin; Xu, Fengli; Fu, Lili; Shan, Xiaoou; Dai, Yuanrong; Zhang, Yali; Liang, Guang

2016-01-01

Sepsis remains a leading cause of death worldwide. Despite years of extensive research, effective drugs to treat sepsis in the clinic are lacking. In this study, we found a novel imidazopyridine derivative, X22, which has powerful anti-inflammatory activity. X22 dose-dependently inhibited lipopolysaccharide (LPS)-induced proinflammatory cytokine production in mouse primary peritoneal macrophages and RAW 264.7 macrophages. X22 also downregulated the LPS-induced proinflammatory gene expression in vitro. In vivo, X22 exhibited a significant protection against LPS-induced death. Pretreatment or treatment with X22 attenuated the sepsis-induced lung and liver injury by inhibiting the inflammatory response. In addition, X22 showed protection against LPS-induced acute lung injury. We additionally found that pretreatment with X22 reduced the inflammatory pain in the acetic acid and formalin models and reduced the dimethylbenzene-induced ear swelling and acetic acid-increased vascular permeability. Together, these data confirmed that X22 has multiple anti-inflammatory effects and may be a potential therapeutic option in the treatment of inflammatory diseases. PMID:27390516

A novel imidazopyridine derivative, X22, attenuates sepsis-induced lung and liver injury by inhibiting the inflammatory response in vitro and in vivo.

PubMed

Ge, Xiangting; Feng, Zhiguo; Xu, Tingting; Wu, Beibei; Chen, Hongjin; Xu, Fengli; Fu, Lili; Shan, Xiaoou; Dai, Yuanrong; Zhang, Yali; Liang, Guang

2016-01-01

Sepsis remains a leading cause of death worldwide. Despite years of extensive research, effective drugs to treat sepsis in the clinic are lacking. In this study, we found a novel imidazopyridine derivative, X22, which has powerful anti-inflammatory activity. X22 dose-dependently inhibited lipopolysaccharide (LPS)-induced proinflammatory cytokine production in mouse primary peritoneal macrophages and RAW 264.7 macrophages. X22 also downregulated the LPS-induced proinflammatory gene expression in vitro. In vivo, X22 exhibited a significant protection against LPS-induced death. Pretreatment or treatment with X22 attenuated the sepsis-induced lung and liver injury by inhibiting the inflammatory response. In addition, X22 showed protection against LPS-induced acute lung injury. We additionally found that pretreatment with X22 reduced the inflammatory pain in the acetic acid and formalin models and reduced the dimethylbenzene-induced ear swelling and acetic acid-increased vascular permeability. Together, these data confirmed that X22 has multiple anti-inflammatory effects and may be a potential therapeutic option in the treatment of inflammatory diseases.

Induction of the chemotactic S100 protein, CP-10, in monocyte/macrophages by lipopolysaccharide.

PubMed

Hu, S P; Harrison, C; Xu, K; Cornish, C J; Geczy, C L

1996-05-01

The murine S100 protein CP-10 is a potent chemotactic factor for murine and human myeloid cells in vivo and in vitro. This is the first report describing regulations of the CP-10 gene by a proinflammatory stimulus, lipopolysaccharide (LPS), in cells of the monocyte/macrophage lineage. Murine monocyte/macrophage-like WEHI 265 and RAW 264.7 cells preexposed to 5 to 50 ng/mL LPS expressed significant levels of CP-10 mRNA 4 hours, and maximal at 20 hours, after a secondary LPS challenge. This was accompanied by increasing levels of cell-associated and released CP-10 protein. In contrast, a single dose of LPS upregulated CP-10 mRNA in elicited peritoneal macrophages, whereas mRNA and protein levels decreased following LPS challenge. The state of macrophage differentiation may control responsiveness as LPS had no effect on CP-10 basal levels in bone marrow derived macrophages. LPS-induced CP-10 expression was controlled at the transcriptional level and nuclear run-on and protein synthesis inhibition assays indicated that LPS priming and challenge of RAW cells occurred via distinct pathways. MRP14, another S100 protein generally coordinately expressed with human MRP8, was not induced by LPS under the same conditions. We propose that CP-10 may play a key role in recruitment of leukocytes into tissues in response to gram-negative bacterial infection.

Bone Marrow Mesenchymal Stem Cells Suppress Acute Lung Injury Induced by Lipopolysaccharide Through Inhibiting the TLR2, 4/NF-κB Pathway in Rats with Multiple Trauma.

PubMed

Li, Dequan; Pan, Xuebo; Zhao, Jing; Chi, Chuang; Wu, Guangyu; Wang, Yuanyuan; Liao, Shiyao; Wang, Cong; Ma, Jihong; Pan, Jingye

2016-06-01

Multiple trauma normally leads to acute lung injury (ALI) and other multiple organ dysfunction syndrome (MODS). Finding effective treatments for ALI remains a medical as well as socioeconomic challenge. Several studies show that bone marrow mesenchymal stem cells (BMSCs) have the potent anti-inflammation activity and transfusion of BMSCs can effectively inhibit inflammatory and autoimmune diseases. In this study, we investigated the TLR2, 4/NF-κB signaling pathway to determine the therapeutic value of BMSCs on lipopolysaccharide (LPS)-induced ALI. To investigate the immunosuppression effects of BMSCs, rats subjected to multiple trauma were administrated with LPS to induce ALI and then treated with BMSCs. The histology of the lung was examined. Serum levels of the pro-inflammatory factors TNFα, interleukin (IL)-6, and IL-1β, as well as anti-inflammatory factor IL-10 were measured at 3, 6, 12, and 24 h after the treatment. Moreover, expressions of TLR2 and TLR4 at the mRNA and protein levels, as well as phosphorylation of p65 in the lungs, were assessed at these time points. We found that BMSCs reduced inflammatory injury, inhibited LPS-induced upregulation of TLR2 and TLR4 expression at the mRNA and protein levels, and compromised p65 phosphorylation. In addition, infusion of BMSCs also downregulated the abundance of pro-inflammatory TNFα, IL-6, and IL-1β and upregulated the abundance of anti-inflammatory IL-10 levels in the serum. Our results suggest that BMSCs suppress the inflammatory reactions through inhibition of the TLR2, 4 mediated NF-κB signal pathway, which hints that BMSCs can potentially be used to treat ALI in multiple trauma.

Effects of O-methylated (-)-epigallocatechin gallate (EGCG) on LPS-induced osteoclastogenesis, bone resorption, and alveolar bone loss in mice.

PubMed

Tominari, Tsukasa; Ichimaru, Ryota; Yoshinouchi, Shosei; Matsumoto, Chiho; Watanabe, Kenta; Hirata, Michiko; Grundler, Florian M W; Inada, Masaki; Miyaura, Chisato

2017-12-01

(-)-Epigallocatechin-3- O -gallate (EGCG), present in green tea, exhibits antioxidant and antiallergy effects. EGCG3″Me, a 3- O -methylated derivative of EGCG, has been reported to show similar biological functions; the inhibitory activity of EGCG3″Me in a mouse allergy model was more potent than that of EGCG, probably due to the efficiency of absorption from the intestine. However, the functional potency of these EGCGs is controversial in each disease model. We previously observed that EGCG suppressed inflammatory bone resorption and prevented alveolar bone loss in a mouse model of periodontosis. In this study, we examined the role of EGCG3″Me in bone resorption using a mouse model of periodontitis. Lipopolysaccharide (LPS)-induced osteoclast formation was suppressed by adding EGCG3″Me to cocultures of osteoblasts and bone marrow cells, and LPS-induced bone resorption was also inhibited by EGCG3″Me in calvarial organ cultures. EGCG3″Me acted on osteoblasts and suppressed prostaglandin E (PGE) production, which is critical for inflammatory bone resorption, by inhibiting the expression of COX-2 and mPGES-1, key enzymes for PGE synthesis. In osteoclast precursor macrophages, EGCG3″Me suppressed RANKL-dependent differentiation into mature osteoclasts. In a mouse model of periodontitis, LPS-induced bone resorption was suppressed by EGCG3″Me in organ culture of mouse alveolar bone, and the alveolar bone loss was further attenuated by the treatment of EGCG3″Me in the lower gingiva in vivo . EGCG3″Me may be a potential natural compound for the protection of inflammatory bone loss in periodontitis.

Lidocaine attenuates lipopolysaccharide-induced inflammatory responses in microglia.

PubMed

Yuan, Tong; Li, Zhiwen; Li, Xinbai; Yu, Gaoqi; Wang, Na; Yang, Xige

2014-11-01

Lidocaine has been used as a local anesthetic with anti-inflammatory properties, but its effects on neuroinflammation have not been well defined. In the present study, we investigated the prophylactic effects of lidocaine on lipopolysaccharide (LPS)-activated microglia and explored the underlying mechanisms. Microglial cells were incubated with or without 1 μg/mL LPS in the presence or absence of lidocaine, a p38 mitogen-activated protein kinase (p38 MAPK) inhibitor (SB203580), a nuclear factor-kappa B (NF-κB) inhibitor (pyrrolidine dithiocarbamate), or small interfering RNA. The protein and expression levels of inflammatory mediators, such as monocyte chemotactic protein 1, nitric oxide, prostaglandin E2, interleukin 1β, and tumor necrosis factor α were measured using enzyme-linked immunosorbent assays and real-time polymerase chain reaction. The effect of lidocaine on NF-κB and p38 MAPK activation was evaluated using enzyme-linked immunosorbent assays, Western blot analysis, and electrophoretic mobility shift assay. Lidocaine (≥2 μg/mL) significantly inhibited the release and expression of nitric oxide, monocyte chemotactic protein 1, prostaglandin E2, interleukin 1β, and tumor necrosis factor α in LPS-activated microglia. Treatment with lidocaine also significantly inhibited the phosphorylation of p38 MAPK and the nuclear translocation of NF-κB p50/p65, increased the protein levels of inhibitor kappa B-α. Furthermore, our study shows that the LPS-induced release of inflammatory mediators was suppressed by SB203580, pyrrolidine dithiocarbamate, and small interfering RNA. Prophylactic treatment with lidocaine inhibits LPS-induced release of inflammatory mediators from microglia, and these effects may be mediated by blockade of p38 MAPK and NF-κB signaling pathways. Copyright © 2014 Elsevier Inc. All rights reserved.

Aesculin inhibits matrix metalloproteinase-9 expression via p38 mitogen activated protein kinase and activator protein 1 in lipopolysachride-induced RAW264.7 cells.

PubMed

Choi, Hee-Jung; Chung, Tae-Wook; Kim, Jai-Eun; Jeong, Han-Sol; Joo, Myungsoo; Cha, Jaeho; Kim, Cheorl-Ho; Ha, Ki-Tae

2012-11-01

Expression of matrix metalloproteinase 9 (MMP-9) may contribute to inflammatory conditions such as arthritis, hepatitis, atherosclerosis, and pulmonary fibrosis, which involves the destruction of the extracellular matrix (ECM). Macrophages stimulated with lipopolysaccharide (LPS) express MMP-9 through the nuclear factor-kappa B (NF-κB) and activator protein 1 (AP-1) signaling pathways. Aesculin, a 6,7-dihydroxycoumarin-6-O-beta-glucopyranoside, has been highlighted for its anti-hepatotoxic, hypouricemic, antioxidative, photo-protective, and anti-apoptotic properties. In this study, we investigated the effects of aesculin on LPS-stimulated MMP-9 production and its regulatory mechanism by using murine macrophage RAW264.7 cells. Aesculin did not trigger any significant cytotoxic effect on RAW264.7 cells at concentration up to 150 μM. Secretion and expression levels of MMP-9, which were highly elevated by LPS treatment, were reduced by the addition of aesculin in a dose-dependent manner. However, gelatinolytic activity of MMP-9 was not reduced by aesculin. Luciferase activity assays and electrophoretic mobility shift assays using RAW264.7 cells showed that the inhibition of MMP-9 expression by aesculin was mediated by AP-1 rather than NF-κB. In addition, aesculin inhibited phosphorylation of p38 MAPK and subsequent activation of c-fos, a component of AP-1 transcription factor, but not JNK, ERK1/2, and c-jun. These findings suggest that aesculin is a potent drug candidate that protects against the inflammatory destruction of ECM. Copyright © 2012 Elsevier B.V. All rights reserved.

Heat stress prevents lipopolysaccharide-induced apoptosis in pulmonary microvascular endothelial cells by blocking calpain/p38 MAPK signalling.

PubMed

Liu, Zhi-Feng; Zheng, Dong; Fan, Guo-Chang; Peng, Tianqing; Su, Lei

2016-08-01

Pulmonary microvascular endothelial cells (PMECs) injury including apoptosis plays an important role in the pathogenesis of acute lung injury during sepsis. Our recent study has demonstrated that calpain activation contributes to apoptosis in PMECs under septic conditions. This study investigated how calpain activation mediated apoptosis and whether heat stress regulated calpain activation in lipopolysaccharides (LPS)-stimulated PMECs. In cultured mouse primary PMECs, incubation with LPS (1 μg/ml, 24 h) increased active caspase-3 fragments and DNA fragmentation, indicative of apoptosis. These effects of LPS were abrogated by pre-treatment with heat stress (43 °C for 2 h). LPS also induced calpain activation and increased phosphorylation of p38 MAPK. Inhibition of calpain and p38 MAPK prevented apoptosis induced by LPS. Furthermore, inhibition of calpain blocked p38 MAPK phosphorylation in LPS-stimulated PMECs. Notably, heat stress decreased the protein levels of calpain-1/2 and calpain activities, and blocked p38 MAPK phosphorylation in response to LPS. Additionally, forced up-regulation of calpain-1 or calpain-2 sufficiently induced p38 MAPK phosphorylation and apoptosis in PMECs, both of which were inhibited by heat stress. In conclusion, heat stress prevents LPS-induced apoptosis in PMECs. This effect of heat stress is associated with down-regulation of calpain expression and activation, and subsequent blockage of p38 MAPK activation in response to LPS. Thus, blocking calpain/p38 MAPK pathway may be a novel mechanism underlying heat stress-mediated inhibition of apoptosis in LPS-stimulated endothelial cells.

Heat stress prevents lipopolysaccharide-induced apoptosis in pulmonary microvascular endothelial cells by blocking calpain/p38 MAPK signalling

PubMed Central

Liu, Zhi-feng; Zheng, Dong; Fan, Guo-chang; Peng, Tianqing; Su, Lei

2016-01-01

Pulmonary microvascular endothelial cells (PMECs) injury including apoptosis plays an important role in the pathogenesis of acute lung injury during sepsis. Our recent study has demonstrated that calpain activation contributes to apoptosis in PMECs under septic conditions. This study investigated how calpain activation mediated apoptosis and whether heat stress regulated calpain activation in lipopolysaccharides (LPS)-stimulated PMECs. In cultured mouse primary PMECs, incubation with LPS (1 µg/ml, 24 h) increased active caspase-3 fragments and DNA fragmentation, indicative of apoptosis. These effects of LPS were abrogated by pre-treatment with heat stress (43 °C for 2 h). LPS also induced calpain activation and increased phosphorylation of p38 MAPK. Inhibition of calpain and p38 MAPK prevented apoptosis induced by LPS. Furthermore, inhibition of calpain blocked p38 MAPK phosphorylation in LPS-stimulated PMECs. Notably, heat stress decreased the protein levels of calpain-1/2 and calpain activities, and blocked p38 MAPK phosphorylation in response to LPS. Additionally, forced up-regulation of calpain-1 or calpain-2 sufficiently induced p38 MAPK phosphorylation and apoptosis in PMECs, both of which were inhibited by heat stress. In conclusion, heat stress prevents LPS-induced apoptosis in PMECs. This effect of heat stress is associated with down-regulation of calpain expression and activation, and subsequent blockage of p38 MAPK activation in response to LPS. Thus, blocking calpain/p38 MAPK pathway may be a novel mechanism underlying heat stress-mediated inhibition of apoptosis in LPS-stimulated endothelial cells. PMID:27325431

Interleukin-18 gene deletion protects against sepsis-induced cardiac dysfunction by inhibiting PP2A activity.

PubMed

Okuhara, Yoshitaka; Yokoe, Shunichi; Iwasaku, Toshihiro; Eguchi, Akiyo; Nishimura, Koichi; Li, Wen; Oboshi, Makiko; Naito, Yoshiro; Mano, Toshiaki; Asahi, Michio; Okamura, Haruki; Masuyama, Tohru; Hirotani, Shinichi

2017-09-15

Interleukin-18 (IL-18) neutralization protects against lipopolysaccharide (LPS)-induced injuries, including myocardial dysfunction. However, the mechanism is yet to be fully elucidated. The aim of the present study was to determine whether IL-18 gene deletion prevents sepsis-induced cardiac dysfunction and to elucidate the potential mechanisms underlying IL-18-mediated cardiotoxicity by LPS. Ten-week-old male wild-type (WT) and IL-18 knockout (IL-18 KO) mice were intraperitoneally administered LPS. Serial echocardiography showed better systolic pump function and less left ventricular (LV) dilatation in LPS-treated IL-18 KO mice compared with those in LPS-treated WT mice. LPS treatment significantly decreased the levels of phospholamban (PLN) and Akt phosphorylation in WT mice compared with those in saline-treated WT mice, while the LPS-induced decrease in the phosphorylation levels was attenuated in IL-18 KO mice compared with that in WT mice. IL-18 gene deletion also attenuated an LPS-induced increase of type 2 protein phosphatase 2A (PP2A) activity, a molecule that dephosphorylates PLN and Akt. There was no difference in type 1 protein phosphatase (PP1) activity. To address whether IL-18 affects PLN and Akt phosphorylation via PP2A activation in cardiomyocytes, rat neonatal cardiac myocytes were cultured and stimulated using 100ng/ml of recombinant rat IL-18. Exogenous IL-18 decreased the level of PLN and Akt phosphorylation in cardiomyocytes. PP2A activity but not PP1 activity was increased by IL-18 stimulation in cardiomyocytes. IL-18 plays a pivotal role in advancing sepsis-induced cardiac dysfunction, and the mechanisms underlying IL-18-mediated cardiotoxicity potentially involve the regulation of PLN and Akt phosphorylation through PP2A activity. Copyright © 2017 Elsevier B.V. All rights reserved.

Simvastatin induces caspase-independent apoptosis in LPS-activated RAW264.7 macrophage cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Yong Chan; Song, Seok Bean; Lee, Mi Hee

Macrophages participate in several inflammatory pathologies such as sepsis and arthritis. We examined the effect of simvastatin on the LPS-induced proinflammatory macrophage RAW264.7 cells. Co-treatment of LPS and a non-toxic dose of simvastatin induced cell death in RAW264.7 cells. The cell death was accompanied by disruption of mitochondrial membrane potential (MMP), genomic DNA fragmentation, and caspase-3 activation. Surprisingly, despite caspase-dependent apoptotic cascade being completely blocked by Z-VAD-fmk, a pan-caspase inhibitor, the cell death was only partially repressed. In the presence of Z-VAD-fmk, DNA fragmentation was blocked, but DNA condensation, disruption of MMP, and nuclear translocation of apoptosis inducing factor weremore » obvious. The cell death by simvastatin and LPS was effectively decreased by both the FPP and GGPP treatments as well as mevalonate. Our findings indicate that simvastatin triggers the cell death of LPS-treated RAW264.7 cells through both caspase-dependent and -independent apoptotic pathways, suggesting a novel mechanism of statins for the severe inflammatory disease therapy.« less

CXC195 suppresses proliferation and inflammatory response in LPS-induced human hepatocellular carcinoma cells via regulating TLR4-MyD88-TAK1-mediated NF-κB and MAPK pathway

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Yiting; Tu, Qunfei; Yan, Wei

Highlights: • CXC195 exhibited significant anti-proliferative effect and induced cell cycle arrest in LPS-induced HepG2 cells. • CXC195 suppressed the release of pro-inflammatory mediators in LPS-induced HepG2 cells. • CXC195 regulated TLR4-MyD88-TAK1-mediated NF-κB and MAPK pathway in LPS-induced HepG2 cells. - Abstract: CXC195 showed strong protective effects in neuronal apoptosis by exerting its antioxidant activity. However, the anti-cancer effects of CXC195 is still with limited acquaintance. Here, we investigated the role of CXC195 in lipopolysaccharide (LPS)-induced human hepatocellular carcinoma (HCC) cells lines (HepG2) and the possible signaling pathways. CXC195 exhibited significant anti-proliferative effect and induced cell cycle arrest in LPS-inducedmore » HepG2 cells. In addition, CXC195 suppressed the release of pro-inflammatory mediators in LPS-induced HepG2 cells, including TNF-α, iNOS, IL-1β, IL-6, CC chemokine ligand (CCL)-2, CCL-22 and epidermal growth factor receptor (EGFR). Moreover, CXC195 inhibited the expressions and interactions of TLR4, MyD88 and TAK1, NF-κB translocation to nucleus and its DNA binding activity, phosphorylation of ERK1/2, p38 and JNK. Our results suggested that treatment with CXC195 could attenuate the TLR4-mediated proliferation and inflammatory response in LPS-induced HepG2 cells, thus might be beneficial for the treatment of HCC.« less

Licofelone Attenuates LPS-induced Depressive-like Behavior in Mice: A Possible Role for Nitric Oxide.

PubMed

Mousavi, Seyyedeh Elaheh; Saberi, Pegah; Ghasemkhani, Naeemeh; Fakhraei, Nahid; Mokhtari, Rezvan; Dehpour, Ahmad Reza

2018-01-01

Licofelone, a dual cyclooxygenase/5-lipoxygenase inhibitor, possesses antioxidant, antiapoptotic, neuroprotective, and anti-inflammatory properties. The aim of the present study was to investigate the effect of licofelone on lipopolysaccharide (LPS)-induced depression in a mouse model and also a possible role for nitric oxide (NO). To elucidate the role of NO on this effect of licofelone (5 and 20 mg/kg, i.p.), L-NAME, a non-specific NO synthase (NOS) inhibitor; aminoguanidine (AG), a specific inducible NOS (iNOS) inhibitor; 7-nitroindazole (7-NI) a preferential neuronal NOS inhibitor (nNOS) and; L-arginine (L-Arg), as a NO donor, were used. The animal's behaviors were evaluated employing forced swimming test (FST), tail suspension test (TST) and open field test (OFT). LPS (0.83 mg/kg, i.p.) induced depressive-like behavior increasing immobility time in FST and TST. Conversely, licofelone (20 mg/kg i.p.) reversed the depressive effect of LPS and lowered the immobility time in FST and TST. On the other hand, pretreatment with L-Arg also reversed the antidepressant-like effect of licofelone (20 mg/kg) in FST and TST. On the other hand, L-NAME (10 and 30 mg/kg), AG (50 and 100 mg/kg) and 7-NI (60 mg/kg) could potentiate licofelone (5 mg/kg) and lowered the immobility duration. NO down-regulation possibly through iNOS and nNOS inhibition may involve in the antidepressant property of licofelone. This article is open to POST-PUBLICATION REVIEW. Registered readers (see "For Readers") may comment by clicking on ABSTRACT on the issue's contents page.

In vivo and in vitro effects of lysine clonixinate on nitric oxide synthase in LPS-treated and untreated rat lung preparations.

PubMed

Franchi, A M; Di Girolamo, G; Farina, M; de los Santos, A R; Martí, M L; Gimeno, M A

2001-04-01

Recent studies have shown that some nonsteroidal antiinflammatory drugs (NSAIDS) inhibited the inducible NO synthase (iNOS) without direct effect on the catalytic activity of this enzyme. This study was conducted to investigate the in vitro and in vivo effects of lysine clonixinate (LC) and indomethacin (INDO) on NOS activity in rat lung preparation. LC is a drug with antiinflammatory, antipyretic, and analgesic action. In the in vitro experiments, rats were injected with saline or lipopolysaccharide (LPS) and killed 6 h after treatment. Lung preparations were incubated with LC at 2.3 x 10(-5) M or 3.8 x 10(-5) M. The minimum concentration did not modify NOS activity in control or LPS-treated rats but the maximum dose inhibited increased NO production induced by LPS. Furthermore, INDO at 10(-6) M had no effect on enzymatic activity in control or LPS-treated rats. In the in vivo experiments, 40 mg/kg of LC were injected ip. Such a dose did not affect basal production of NO. When LC and LPS were injected simultaneously 6 h before sacrifice, a significant decrease in LPS-induced NOS activity was observed. INDO 10 mg/kg injected in control animals had no effect on NOS activity and did not block LPS induced stimulation of NO production when injected simultaneously. Finally, when LC (40 mg/kg) was injected 3 h after LPS, the enzymatic activity remained unchanged. Expression of iNOS was detected by Western blotting in rats treated with LPS plus 4, 10, 20, and 40 mg/kg of LC. The lowest dose was the only one showing no effect on LPS-induced increase of iNOS. In short, LC is a NSAID with inhibitory action on the expression of LPS-induced NOS, effect that was not seen with INDO in our experimental conditions. Copyright 2001 Academic Press.

Lipopolysaccharide stimulates HepG2 human hepatoma cells in the presence of lipopolysaccharide-binding protein via CD14.

PubMed

Nanbo, A; Nishimura, H; Muta, T; Nagasawa, S

1999-02-01

Lipopolysaccharide (LPS)-binding protein (LBP), an opsonin for activation of macrophages by bacterial LPS, is synthesized in hepatocytes and is known to be an acute phase protein. Recently, cytokine-induced production of LBP was reported to increase 10-fold in hepatocytes isolated from LPS-treated rats, compared with those from normal rats. However, the mechanism by which the LPS treatment enhances the effect of cytokines remains to be clarified. In the present study, we examined whether LPS alone or an LPS/LBP complex directly stimulates the hepatocytes, leading to acceleration of the cytokine-induced LBP production. HepG2 cells (a human hepatoma cell line) were shown to express CD14, a glycosylphosphatidylinositol-anchored LPS receptor, by both RT/PCR and flow cytometric analyses. An LPS/LBP complex was an effective stimulator for LBP and CD14 production in HepG2 cells, but stimulation of the cells with either LPS or LBP alone did not significantly accelerate the production of these proteins. The findings were confirmed by semiquantitative RT/PCR analysis of mRNA levels of LBP and CD14 in HepG2 cells after stimulation with LPS alone and an LPS/LBP complex. In addition, two monoclonal antibodies (mAbs) to CD14 (3C10 and MEM-18) inhibited LPS/LBP-induced cellular responses of HepG2 cells. Furthermore, prestimulation of HepG2 cells with LPS/LBP augmented cytokine-induced production and gene expression of LBP and CD14. All these findings suggest that an LPS/LBP complex, but not free LPS, stimulates HepG2 cells via CD14 leading to increased basal and cytokine-induced LBP and CD14 production.

Propofol pretreatment attenuates LPS-induced granulocyte-macrophage colony-stimulating factor production in cultured hepatocytes by suppressing MAPK/ERK activity and NF-{kappa}B translocation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jawan, Bruno; Kao, Y.-H.; Department of Biological Sciences, National Sun Yat-Sen University, 70 Lien-Hai Road, Kaohsiung 804, Taiwan

Propofol (PPF), a widely used intravenous anesthetic for induction and maintenance of anesthesia during surgeries, was found to possess suppressive effect on host immunity. This study aimed at investigating whether PPF plays a modulatory role in the lipopolysaccharide (LPS)-induced inflammatory cytokine expression in a cell line of rat hepatocytes. Morphological observation and viability assay showed that PPF exhibits no cytotoxicity at concentrations up to 300 {mu}M after 48 h incubation. Pretreatment with 100 {mu}M PPF for 24 h prior to LPS stimulation was performed to investigate the modulatory effect on LPS-induced inflammatory gene production. The results of semi-quantitative RT-PCR demonstratedmore » that PPF pretreatment significantly suppressed the LPS-induced toll-like receptor (TLR)-4, CD14, tumor necrosis factor (TNF)-{alpha}, and granulocyte-macrophage colony-stimulating factor (GM-CSF) gene expression. Western blotting analysis showed that PPF pretreatment potentiated the LPS-induced TLR-4 downregulation. Flow cytometrical analysis revealed that PPF pretreatment showed no modulatory effect on the LPS-upregulated CD14 expression on hepatocytes. In addition, PPF pretreatment attenuated the phosphorylation of mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK) and I{kappa}B{alpha}, as well as the nuclear translocation of NF-{kappa}B primed by LPS. Moreover, addition of PD98059, a MAPK kinase inhibitor, significantly suppressed the LPS-induced NF-{kappa}B nuclear translocation and GM-CSF production, suggesting that the PPF-attenuated GM-CSF production in hepatocytes may be attributed to its suppressive effect on MAPK/ERK signaling pathway. In conclusion, PPF as an anesthetic may clinically benefit those patients who are vulnerable to sepsis by alleviating sepsis-related inflammatory response in livers.« less

Anti-inflammatory activity of 4-methoxyhonokiol is a function of the inhibition of iNOS and COX-2 expression in RAW 264.7 macrophages via NF-kappaB, JNK and p38 MAPK inactivation.

PubMed

Zhou, Hong Yu; Shin, Eun Myoung; Guo, Lian Yu; Youn, Ui Joung; Bae, KiHwan; Kang, Sam Sik; Zou, Li Bo; Kim, Yeong Shik

2008-05-31

The extracts or constituents from the bark of Magnolia (M.) obovata are known to have many pharmacological activities. 4-Methoxyhonokiol, a neolignan compound isolated from the stem bark of M. obovata, was found to exhibit a potent anti-inflammatory effect in different experimental models. Pretreatment with 4-methoxyhonokiol (i.p.) dose-dependently inhibited the dye leakage and paw swelling in an acetic-acid-induced vascular permeability assay and a carrageenan-induced paw edema assay in mice, respectively. In the lipopolysaccharide (LPS)-induced systemic inflammation model, 4-methoxyhonokiol significantly inhibited plasma nitric oxide (NO) release in mice. To identify the mechanisms underlying this anti-inflammatory action, we investigated the effect of 4-methoxyhonokiol on LPS-induced responses in a murine macrophage cell line, RAW 264.7. The results demonstrated that 4-methoxyhonokiol significantly inhibited LPS-induced NO production as well as the protein and mRNA expressions of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2). Furthermore, 4-methoxyhonokiol inhibited LPS-mediated nuclear factor-kappaB (NF-kappaB) activation via the prevention of inhibitor kappaB (IkappaB) phosphorylation and degradation. 4-Methoxyhonokiol had no effect on the LPS-induced phosphorylation of extracellular signal-regulated kinase (ERK), whereas it attenuated the phosphorylation of p38 mitogen-activated protein kinase (p38 MAPK) and c-Jun NH2-terminal kinase (JNK) in a concentration-dependent manner. Taken together, our data suggest that 4-methoxyhonokiol is an active anti-inflammatory constituent of the bark of M. obovata, and that its anti-inflammatory property might be a function of the inhibition of iNOS and COX-2 expression via down-regulation of the JNK and p38 MAP kinase signal pathways and inhibition of NF-kappaB activation in RAW 264.7 macrophages.

Silibinin inhibits the fibrotic responses induced by cigarette smoke via suppression of TGF-β1/Smad 2/3 signaling.

PubMed

Ko, Je-Won; Shin, Na-Rae; Park, Sung-Hyeuk; Lee, In-Chul; Ryu, Jung-Min; Kim, Ha-Jung; Cho, Young-Kwon; Kim, Jong-Choon; Shin, In-Sik

2017-08-01

Cigarette smoke (CS) is generally accepted as a major contributor to chronic obstructive pulmonary disease (COPD) which is characterized by chronic inflammation, fibrotic response, and airway obstruction. In this study, we investigated the preventive effects of silibinin, an active constitute of silymarin on CS and lipopolysaccharide (LPS) exposure-induced fibrotic response. Mice were exposed to CS for 1 h per day (8 cigarettes per day) for 4 weeks. On day 12 and 26, mice were treated with LPS intranasally. Silibinin (10 or 20 mg/kg) was administered orally 1 h before CS exposure. Silibinin markedly decreased the inflammatory cell count in the bronchoalveolar lavage fluid, and reduced levels of proinflammatory mediators. Silibinin suppressed CS + LPS-induced collagen deposition in lung tissue, as evidenced via immunohistochemistry and Masson's trichrome stain. Additionally, silibinin effectively inhibited CS + LPS-mediated expression of transforming growth factor-β1 (TGF-β1) and Smad 2/3 phosphorylation. Taken together, our data indicate that silibinin effectively inhibits the fibrotic response induced by CS + LPS exposure, possibly via suppression of TGF-β1/Smad 2/3 signaling, which results in reduced collagen deposition. These findings suggest that silibinin has therapeutic potential for the treatment of COPD. Copyright © 2017 Elsevier Ltd. All rights reserved.

Esculin exhibited anti-inflammatory activities in vivo and regulated TNF-α and IL-6 production in LPS-stimulated mouse peritoneal macrophages in vitro through MAPK pathway.

PubMed

Niu, Xiaofeng; Wang, Yu; Li, Weifeng; Zhang, Hailin; Wang, Xiumei; Mu, Qingli; He, Zehong; Yao, Huan

2015-12-01

Esculin, a coumarinic derivative found in Aesculus hippocastanum L. (Horse-chestnut), has been reported to have potent anti-inflammatory properties. The present study is designed to investigate the protective effects of esculin on various inflammation models in vivo and in vitro and to clarify the possible mechanism. Induced-animal models of inflammation and lipopolysaccharide (LPS)-challenged mouse peritoneal macrophages were used to examine the anti-inflammatory activity of esculin. In present study, xylene-induced mouse ear edema, carrageenan-induced rat paw edema, and carrageenan-induced mouse pleurisy were attenuated by esculin. In vitro, the pro-inflammatory cytokine levels of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in supernatant were reduced by esculin. Meanwhile, we found that esculin significantly inhibited LPS-induced activation of mitogen-activated protein kinase (MAPK) pathway in peritoneal macrophages. These results suggest that esculin has potent anti-inflammatory activities in vivo and in vitro, which may involve the inhibition of the MAPK pathway. Esculin may be a promising preventive agent for inflammatory diseases in human. Copyright © 2015 Elsevier B.V. All rights reserved.